LVTest VISUALCONNX Application manual LVTest VISUALCONNX Application Version 6.5.0 - bernard 0 0.

Document Type User manual

Project Number and Name LVTest VISUALCONNX Application

Document No. J001518 Version 6.5.0 Last Modified 20/03/2014 18:03:00

Create Date 29/04/2013 11:04:00 Checked by

Author Bernard Leak Approved by

Hawkesyard Hall, Armitage Park, RUGELEY, Staffordshire, WS15 1PU

Tel: 01889 574400, Fax: 01889 576779, Email: [email protected]

Copyright © add2 bernard of 157 J001518 V6.5.0 LVTest VISUALCONNX Application.doc

LVTest VISUALCONNX Application

LVTGO-VBS GUI V6.5.0

Supports LVTGO-VBS Firmware V1.2.0 to V5.1.7

Requires VISUALCONNX V3.0 or later

User manual LVTest VISUALCONNX Application Version 6.5.0 - bernard

Copyright add2 bernard of 157 J001518 V6.5.0 LVTest VISUALCONNX Application.doc

Change History

Date of Issue Version No. Details of Change

14th Nov. 2008 1.0 First Release of documentation for GUI V2.0.5

31st March 2009 1.0.1 Update to support GUI version 3.0.0

22nd April 2009 1.1 Update to support GUI version 3.0.3

12th May 2009 1.2 Update to support LV Test GUI Version 3.0.5

3rd September 2009 1.3 Update to support LV Test GUI Version 3.0.6

22nd September 2009 1.3.1 Update to support LV Test GUI Version 3.0.7

16th November 2009 1.3.3 Update for Firmware 1.3.3, GUI Version 3.0.8 RC2

30th November 2009 1.3.4 Update for Firmware 1.3.4, GUI Version 3.0.8 RC3

18th December 2009 1.3.5 Update for Firmware 1.3.5, GUI Version 3.0.9 PRE

6th January 2010 1.4.0 Update for Firmware 1.4.0, GUI Version 3.5.0 PRE



25th February 2010 2.0.4 Update for Firmware 2.0.4 GUI Version 3.9.N

17th February 2011 3.0.0 Update for Firmware 3.0.0 GUI Version 4.0

9th November 2011 4.0.0 Update for Firmware 4.0.0 GUI Version 5.0

13th June 2012 5.0.0 Update for Firmware 5.0.0 GUI Version 6.0

4th February 2013 6.1.0 Update for Firmware 5.1.1 GUI Version 6.1

29th April 2013 6.1.1 Update for Firmware 5.1.2 GUI Version 6.1.1

20th March 2014 6.5.0 Update for Firmware 5.1.7 GUI Version 6.5.0



Contents

LVTEST VISUALCONNX APPLICATION ................................................................................................. 1

CHANGE HISTORY ..................................................................................................................................... 2

CONTENTS ................................................................................................................................................... 3

INTRODUCTION .......................................................................................................................................... 8

1 CONVENTIONS IN THIS DOCUMENT .......................................................................................... 10

2 OVERVIEW ........................................................................................................................................ 10

3 HARDWARE ...................................................................................................................................... 11

3.1 [HARDWARE] THE LVTGO-VBS GROUND TERMINALS ...................................................................... 11 3.1.1 [Hardware] Small Units .......................................................................................................... 12 3.1.2 [Hardware] Mid-Sized Units.................................................................................................... 13 3.1.3 [Hardware] Rack-Mounted Units ............................................................................................. 13

4 SOFTWARE........................................................................................................................................ 15

4.1 [SOFTWARE]: LOAD THE LVTEST APPLICATION ................................................................................. 15 4.2 [SOFTWARE]: RUN THE LVTEST APPLICATION ................................................................................... 15

5 THE MAIN MENU ............................................................................................................................. 18

5.1 [MENU]: VIEW THE APPLICATION HELP DOCUMENT ............................................................................. 18 5.2 [MENU]: THE TAB-BAR ...................................................................................................................... 18 5.3 [MENU]: SELECTING AND USING A WAVEFORM .................................................................................. 19

6 THE WAVEFORM MAIN FORM ..................................................................................................... 21

6.1 [MAIN]: RETURNING TO THE MAIN MENU............................................................................................ 22 6.2 [MAIN]: SAVE THE CURRENT SETTINGS ............................................................................................... 22 6.3 [MAIN]: VIEWING THE APPLICATION HELP DOCUMENT ........................................................................ 22 6.4 [MAIN]: THE TAB-BAR ....................................................................................................................... 23 6.5 [MAIN]: LOADING WAVEFORM SETTINGS FROM PROFILES .................................................................... 24 6.6 [MAIN]: MODIFYING THE PARAMETERS THAT DEFINE THE WAVEFORM ................................................. 25 6.7 [MAIN]: RUNNING WAVEFORMS ......................................................................................................... 25

6.7.1 [Main]: Playing from and to a specified cycle .......................................................................... 25 6.7.2 [Main]: Starting, Pausing, Resuming and Stopping .................................................................. 26

6.8 [MAIN]: INSPECTING AND LOGGING PROGRESS AND OUTPUTS FROM THE LVT ...................................... 27 6.8.1 [Main]: Logging data from the LVT ......................................................................................... 30

6.9 [MAIN]: SELECTING A SPECIFIC CAPTURED WAVEFORM...................................................................... 31 6.10 [MAIN]: PRE-VIEWING CAPTURED AND MICRO-CUTOUTS WAVEFORMS .......................................... 32

7 THE VOLTAGE CONFIGURATIONS FORM ................................................................................. 33

7.1 [VOLTAGE]: RETURN TO THE PREVIOUS FORM .................................................................................... 33 7.2 [VOLTAGE]: SAVE THE CURRENT SETTINGS......................................................................................... 33 7.3 [VOLTAGE]: VIEWING THE APPLICATION HELP DOCUMENT .................................................................. 34 7.4 [VOLTAGE]: THE TAB-BAR ................................................................................................................. 34 7.5 [VOLTAGE]: ENABLING A, B AND C OUTPUTS IN A RANDOM CRANKING WAVEFORM............................ 35 7.6 [VOLTAGE]: THE NUMBER OF EFTBN STEPS ...................................................................................... 35 7.7 [VOLTAGE]: VOLTAGES DEFINING THE WAVEFORM ............................................................................. 35 7.8 [VOLTAGE]: VOLTAGE INSTABILITY WHILE LOADING PROFILES .......................................................... 36 7.9 [VOLTAGE]: SPECIAL CONSTRAINTS FOR RANDOM CRANKING WAVEFORMS ......................................... 36 7.10 [VOLTAGE]: ADDITIONAL VOLTAGE PARAMETERS .......................................................................... 37 7.11 [VOLTAGE]: VOLTAGE PARAMETERS FOR MICRO-CUTOUTS ........................................................... 38 7.12 [VOLTAGE]: THE WAVEFORM DIAGRAM ......................................................................................... 39 7.13 [VOLTAGE]: THE HELP TEXT .......................................................................................................... 39



8 THE TIMING AND FREQUENCY CONFIGURATIONS FORM ................................................... 40

8.1 [TIME]: RETURN TO THE PREVIOUS FORM ........................................................................................... 40 8.2 [TIME]: SAVING THE SETTINGS ........................................................................................................... 40 8.3 [TIME]: VIEWING THE APPLICATION HELP DOCUMENT ......................................................................... 41 8.4 [TIME]: THE TAB-BAR ........................................................................................................................ 41 8.5 [TIME]: TIMES AND FREQUENCIES DEFINING THE WAVEFORM .............................................................. 41

8.5.1 [Main]: Timing Parameters for Micro-Cutouts waveforms ....................................................... 42 8.6 [TIME]: SCALING THE DURATION OF TIME-STEPS ................................................................................. 43 8.7 [TIME]: EFTBN CONFIGURATION ....................................................................................................... 44 8.8 [TIME]: THE WAVEFORM DIAGRAM .................................................................................................... 45 8.9 [TIME]: THE HELP-TEXT .................................................................................................................... 45 8.10 [TIME]: THE OUTPUT FILTER CONTROL .......................................................................................... 46 8.11 [TIME]: WAVEFORM-SPECIFIC DETAILS .......................................................................................... 47

9 SETTINGS AND RANDOMISATION ............................................................................................... 48

9.1 [SETTINGS]: FIXED (NO RANDOMISATION) .......................................................................................... 49 9.2 [SETTINGS]: UNIFORMLY DISTRIBUTED .............................................................................................. 49 9.3 [SETTINGS]: NORMAL DISTRIBUTIONS ................................................................................................ 49 9.4 [SETTINGS]: 1/X2

DISTRIBUTION.......................................................................................................... 50 9.5 [SETTINGS]: RANDOM SEEDS.............................................................................................................. 50 9.6 [SETTINGS]: RESOLUTION .................................................................................................................. 51 9.7 [SETTINGS]: SCALING TIME SETTINGS ................................................................................................ 51

10 THE PARAMETER MONITORING FORM .................................................................................... 53

10.1 [PARAMETERS]: RETURN TO THE PREVIOUS FORM .......................................................................... 53 10.2 [PARAMETERS]: VIEWING THE APPLICATION HELP DOCUMENT ........................................................ 53 10.3 [PARAMETERS]: THE TAB-BAR ....................................................................................................... 54 10.4 [PARAMETERS]: SELECTING PARAMETERS TO INSPECT .................................................................... 54 10.5 [PARAMETERS]: THE MAIN PARAMETER VALUES STRIP-CHART ........................................................ 55 10.6 [PARAMETERS]: CONTROLLING PARAMETER STREAMING ................................................................ 55

11 THE INPUT TRIGGER CONFIGURATION FORM ....................................................................... 56

11.1 [INPUT TRIGGERS]: RETURN TO THE PREVIOUS FORM...................................................................... 56 11.2 [INPUT TRIGGERS]: SAVING THE SETTINGS ..................................................................................... 57 11.3 [INPUT TRIGGERS]: VIEWING THE APPLICATION HELP DOCUMENT ................................................... 57 11.4 [INPUT TRIGGERS]: THE TAB-BAR .................................................................................................. 57 11.5 [INPUT TRIGGERS]: INPUT TRIGGERS .............................................................................................. 57 11.6 [INPUT TRIGGERS]: THE HELP-TEXT .............................................................................................. 59 11.7 [INPUT TRIGGERS]: THE OBSOLETE DEFAULT CAN TRIGGER .......................................................... 60

12 THE OUTPUT TRIGGER CONFIGURATION FORM ................................................................... 61

12.1 [OUTPUT TRIGGERS]: RETURN TO THE PREVIOUS FORM .................................................................. 61 12.2 [OUTPUT TRIGGERS]: SAVING THE SETTINGS .................................................................................. 61 12.3 [OUTPUT TRIGGERS]: VIEWING THE APPLICATION HELP DOCUMENT ................................................ 62 12.4 [OUTPUT TRIGGERS]: THE TAB-BAR............................................................................................... 62 12.5 [OUTPUT TRIGGERS]: USING THE ADDITIONAL CONFIGURATION TRIGGER FOR SCRIPTED

CONFIGURATION CHANGES .......................................................................................................................... 63 12.6 [OUTPUT TRIGGERS]: TRIGGERING RAMP UP AND DOWN WAVEFORMS ........................................... 63 12.7 [OUTPUT TRIGGERS]: OUTPUT TRIGGERS ....................................................................................... 64 12.8 [OUTPUT TRIGGERS]: TRIGGERING ON A SCALED TIME-STEP ........................................................... 65 12.9 [OUTPUT TRIGGERS]: OUTPUT TRIGGERS - ANALOGUE.................................................................... 65 12.10 [OUTPUT TRIGGERS]: OUTPUT TRIGGERS – CAN ............................................................................ 66 12.11 [OUTPUT TRIGGERS]: ADDITIONAL ANALOGUE TRIGGERS ............................................................... 66 12.12 [OUTPUT TRIGGERS]: THE HELP-TEXT ........................................................................................... 69 12.13 [OUTPUT TRIGGERS]: CHANGES TO CONTROLS FOR MICRO-CUTOUTS ............................................. 69

13 THE MISCELLANEOUS SETTINGS FORM................................................................................... 71

13.1 [MISC]: RETURN TO THE PREVIOUS FORM ....................................................................................... 71 13.2 [MISC]: NAVIGATING TO SPECIFIC FORMS ...................................................................................... 71 13.3 [MISC]: VIEWING THE APPLICATION HELP DOCUMENT .................................................................... 72 13.4 [MISC]: THE TAB-BAR ................................................................................................................... 72



13.5 [MISC]: THE CYCLE-NUMBER STREAMING CONTROL ...................................................................... 73 13.6 [TIME]: THE GO FEEDBACK CONTROL ........................................................................................... 74 13.7 [MISC]: THE LOGGING-COMPRESSION CONTROLS............................................................................ 74 13.8 [MISC]: THE DATA-RETENTION CONTROL ....................................................................................... 75 13.9 [MISC]: THE READBACKS STRIP-CHART .......................................................................................... 76

14 THE ERROR STATUS AND SPECIAL VALUES FORM................................................................ 77

14.1 [SPECIAL]: RETURN TO THE PREVIOUS FORM .................................................................................. 77 14.2 [SPECIAL]: NAVIGATING TO SPECIFIC FORMS .................................................................................. 77 14.3 [SPECIAL]: VIEWING THE APPLICATION HELP DOCUMENT ................................................................ 78 14.4 [SPECIAL]: THE TAB-BAR .............................................................................................................. 78 14.5 [SPECIAL]: ERROR STATUS ............................................................................................................ 79 14.6 [SPECIAL]: VERSION NUMBERS ...................................................................................................... 80 14.7 [SPECIAL]: MAKE SETTINGS PERSISTENT ........................................................................................ 81 14.8 [SPECIAL]: THE SPECIAL VALUES INTERFACE................................................................................. 82 14.9 [SPECIAL]: THE OUTPUT-RANGE CONTROLS.................................................................................... 83

15 THE TRIP STATUS FORM ............................................................................................................... 85

15.1 [TRIPS]: RETURN TO THE PREVIOUS FORM ...................................................................................... 85 15.2 [TRIPS]: NAVIGATING TO SPECIFIC FORMS ...................................................................................... 85 15.3 [TRIPS]: VIEWING THE APPLICATION HELP DOCUMENT .................................................................... 86 15.4 [TRIPS]: THE TAB-BAR .................................................................................................................. 86 15.5 [TRIPS]: INSPECTING THE TRIP STATE ............................................................................................. 87 15.6 [TRIPS]: TRIP-LIKE BEHAVIOUR ..................................................................................................... 87 15.7 [TRIPS]: INSPECTING THE TRIP LOG ................................................................................................ 88 15.8 [TRIPS]: INSPECTING THE THERMAL INFORMATION ......................................................................... 90

16 THE HIL INPUTS FORM .................................................................................................................. 91

16.1 [HIL]: RETURN TO THE PREVIOUS FORM ........................................................................................ 91 16.2 [HIL]: NAVIGATING TO SPECIFIC FORMS ........................................................................................ 92 16.3 [HIL]: VIEWING THE APPLICATION HELP DOCUMENT ...................................................................... 92 16.4 [HIL]: THE TAB-BAR ..................................................................................................................... 92 16.5 [HIL]: VIEWING THE APPLICATION HELP DOCUMENT ...................................................................... 93 16.6 [HIL]: THE HIL INPUTS SHOWN NUMERICALLY, AND AS BINARY DATA............................................ 93 16.7 [HIL]: SETTING THE HIL READBACK INTERVAL ............................................................................. 93 16.8 [HIL]: SELECTING THE HIL INPUT TO SHOW ON THE WAVEFORM MAIN FORM ................................. 94 16.9 [HIL]: THE HIL STRIP-CHART ....................................................................................................... 94

17 EXTREMELY FAST TRANSIENT BURST NOISE ......................................................................... 95

17.1 [EFTBN]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION .............................................. 95 17.2 [EFTBN]: MODIFY THE VOLTAGE PARAMETERS ............................................................................. 96

17.2.1 [EFTBN]: Setting the number of steps ................................................................................. 96 17.3 [EFTBN]: MODIFY THE TIME PARAMETERS.................................................................................... 97

18 RANDOM CRANKING WAVEFORM ............................................................................................. 98

18.1 [CRANK]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION ............................................... 98 18.2 [CRANK]: MODIFY THE VOLTAGE PARAMETERS.............................................................................. 99 18.3 [CRANK]: VOLTAGE CONSTRAINTS FOR RANDOM CRANKING........................................................ 100 18.4 [CRANK]: MODIFY THE TIME AND FREQUENCY PARAMETERS ........................................................ 101

19 RAMP UP AND DOWN.................................................................................................................... 102

19.1 [RAMP]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION ............................................... 102 19.2 [RAMP]: MODIFY THE VOLTAGE PARAMETERS.............................................................................. 103 19.3 [RAMP]: MODIFY THE TIME PARAMETERS .................................................................................... 104

20 CONSTANT VOLTAGE .................................................................................................................. 105

20.1 [CONSTANT]: MODIFY THE VOLTAGE PARAMETERS ...................................................................... 106 20.2 [CONSTANT]: MODIFY THE TIME PARAMETERS ............................................................................. 107

21 ALTERNATIVE RAMP ................................................................................................................... 108

21.1 [ALT. RAMP]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION ....................................... 109



21.2 [ALT. RAMP]: MODIFY THE VOLTAGE PARAMETERS ..................................................................... 109 21.3 [ALT. RAMP]: MODIFY THE TIME PARAMETERS ............................................................................ 110

22 CAPTURED WAVEFORMS ............................................................................................................ 111

22.1 [CAPTURED]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION........................................ 112 22.2 [CAPTURED]: MODIFY THE VOLTAGE PARAMETERS ...................................................................... 112 22.3 [CAPTURED]: MODIFY THE TIME PARAMETERS ............................................................................. 113 22.4 [CAPTURED]: IMPORTING, RESAMPLING AND MANAGING CAPTURED WAVEFORMS ....................... 113

23 MICRO-CUTOUTS WAVEFORMS ................................................................................................ 114

23.1 MICRO-CUTOUTS PREVIEW ......................................................................................................... 115 23.2 [CAPTURED]: CHANGE AND VIEW DURATION AND CYCLE INFORMATION........................................ 115 23.3 [CAPTURED]: MODIFY THE VOLTAGE PARAMETERS ...................................................................... 115 23.4 [CAPTURED]: MODIFY THE TIME PARAMETERS ............................................................................. 117

24 THE CAPTURED IMPORT FORM ................................................................................................ 118

24.1 [IMPORT]: SCANNING THE CURRENT WAVEFORM DIRECTORY ........................................................ 119 24.2 [IMPORT]: RETURN TO THE PREVIOUS FORM ................................................................................. 119 24.3 [IMPORT]: VIEWING THE APPLICATION HELP DOCUMENT ............................................................... 119 24.4 [IMPORT]: THE TAB-BAR ............................................................................................................. 120 24.5 [IMPORT]: DESTINATION FOLDER CONTROL ................................................................................. 120 24.6 [IMPORT]: ACTION BUTTONS ....................................................................................................... 120 24.7 [IMPORT]: IMPORTED WAVEFORMS LIST-BOX ............................................................................... 122 24.8 [IMPORT]: ACTIVITY LOG CONTROLS ........................................................................................... 122 24.9 [IMPORT]: WAVEFORM DETAILS DISPLAY .................................................................................... 124 24.10 [IMPORT]: PROGRESS BAR ........................................................................................................... 125 24.11 [IMPORT]: HELP FRAME ............................................................................................................... 125

25 THE CAPTURED RESAMPLE FORM ........................................................................................... 126

25.1 [RESAMPLE]: SCANNING ............................................................................................................. 126 25.2 [RESAMPLE]: RETURN TO THE PREVIOUS FORM ............................................................................ 127 25.3 [RESAMPLE]: VIEWING THE APPLICATION HELP DOCUMENT .......................................................... 127 25.4 [RESAMPLE]: THE TAB-BAR ......................................................................................................... 127 25.5 [RESAMPLE]: WAVEFORM FOLDER CONTROL ............................................................................... 128 25.6 [RESAMPLE]: THE LIST-BOXES ..................................................................................................... 128 25.7 [RESAMPLE]: SPACE USED FRAME ............................................................................................... 129 25.8 [RESAMPLE]: ACTIVITY LOG CONTROLS ...................................................................................... 130 25.9 [RESAMPLE]: ACTION BUTTONS .................................................................................................. 130 25.10 [RESAMPLE]: WAVEFORM DATA FRAME ...................................................................................... 131 25.11 [RESAMPLE]: GRAPH ................................................................................................................... 132 25.12 [RESAMPLE]: HELP TEXT ............................................................................................................ 132 25.13 [RESAMPLE]: PROGRESS BAR ...................................................................................................... 133 25.14 [RESAMPLE]: QUICK HELP .......................................................................................................... 133 25.15 [RESAMPLE]: RESAMPLING CONTROLS ........................................................................................ 134

26 GENERAL DISCUSSION OF THE RESAMPLING PROCESS .................................................... 137

26.1 [DISCUSSION]: PRECISION SETTINGS FOR THE VOLTAGES .............................................................. 137 26.2 [DISCUSSION]: OPTIONS FOR THE TIME-STAMP DATA .................................................................... 137 26.3 [DISCUSSION]: THE STAGES OF RE-SAMPLING ............................................................................... 138 26.4 [DISCUSSION]: SPECIAL CONSIDERATIONS FOR REPEAT-COUNTS ................................................... 139

27 THE CAPTURED TRANSFER FORM ........................................................................................... 140

27.1 [TRANSFER]: SCANNING .............................................................................................................. 141 27.2 [TRANSFER]: RETURN TO THE PREVIOUS FORM ............................................................................. 141 27.3 [TRANSFER]: VIEWING THE APPLICATION HELP DOCUMENT .......................................................... 142 27.4 [TRANSFER]: THE TAB-BAR ......................................................................................................... 142 27.5 [TRANSFER]: WAVEFORM FOLDER CONTROL ............................................................................... 142 27.6 [TRANSFER]: THE LIST-BOXES ..................................................................................................... 142 27.7 [TRANSFER]: ACTIVITY LOG CONTROLS ...................................................................................... 143 27.8 [TRANSFER]: ACTION BUTTONS................................................................................................... 144 27.9 [TRANSFER]: BUSY LABEL .......................................................................................................... 147



27.10 [TRANSFER]: SPACE USED FRAME................................................................................................ 147 27.11 [TRANSFER]: WAVEFORM DETAILS ............................................................................................. 147 27.12 [TRANSFER]: HELP FRAME .......................................................................................................... 149 27.13 [TRANSFER]: PROGRESS BAR....................................................................................................... 149

28 REPLAYING PROBLEMATIC WAVEFORM CYCLES .............................................................. 150

29 TEST STANDARDS ......................................................................................................................... 151

29.1 CI 230 – SOME SPECIAL OBSERVATIONS ....................................................................................... 152

30 SCRIPTING USING THE COM INTERFACE ............................................................................... 153

30.1 [SCRIPTING]: COM SCRIPTING AND INPUT TRIGGERS .................................................................... 153 30.1.1 [Scripting]: Using an Analogue Input Trigger from COM .................................................. 154 30.1.2 [Scripting]: Using a User-Configured CAN Trigger from COM ......................................... 154 30.1.3 [Scripting]: Using a Configuration Trigger from COM ...................................................... 155 30.1.4 [Scripting]: Changes to the COM input trigger interface ................................................... 155 30.1.5 [Scripting]: Converting old COM scripts using Default CAN triggers ................................ 156 30.1.6 [Scripting]: Voltages over 20V in configuring 20V LVTGO-VBS units ............................... 156

31 RECOMMENDED SETTINGS FOR RUNNING THE APPLICATION........................................ 157



Introduction

This document describes the use of the Low Voltage Test Suite, a VISUALCONNX scripting

application. It is available as a PDF file, LVTestApplication.pdf and as a Windows Help file,

LVTestApplication.chm

What is the Low Voltage Test Suite?

The Low Voltage Test Suite is a suite of hardware and software that can create simulations of

real-world waveforms such as engine cranking tests, battery ramp tests and fast transient

generation (“rusty file”) tests.

These tests are defined using modelling techniques which simplify and parametrise the

waveform shapes. This technique allows for long-term testing to take place without a lot of

data storage being necessary. In addition to low storage requirements, the technique allows

for controlled random variation of voltages and time periods using repeatable waveforms.

Should the unit under test fail, the waveforms which produced the failure can be exactly

reproduced.

In addition to the sophisticated software techniques, leading-edge power drive hardware is

used to generate very fast output transitions at high currents, thus exceeding the transient

performance of most modern power supplies. In fact, for nominal output voltages (up to 20V

or 30V, depending on the unit), a simple power supply and vehicle battery can be used to

reduce system costs while maintaining very good output characteristics. An important

feature is that falling output voltages can be actively driven down towards the ground

voltage, which can help overcome distortions due to the impedance of the device under test.

The supplied software package runs as a VISUALCONNX GUI scripting application.

VISUALCONNX is a powerful visualisation tool running under Microsoft WindowsTM

which provides a platform that can communicate with the low voltage test hardware.

The user interface also gives access to diagnostics such as the heatsink temperature of the

tester and the status of thermal and over-power trips. Some values can also be logged to hard

disk if test evidence is required.

For a detailed reference to the “Low Voltage Tester Ground Offset - Vehicle Battery

Simulator”, please refer to the LVTGO-VBS - Specification Sheet.

The GUI supports importing user-captured waveforms and transferring them to the LVTGO-

VBS unit to be replayed. This is documented in the chapters on the Captured Import,

Captured Resampling and Captured Transfer forms. Please also read the chapter on the

resampling process.

The output of the LVTGO-VBS unit can be re-scaled to act as an input to an external power

amplifier. The current support is detailed under the heading Special_Values_Output_Range.

If you have custom requirements, please get in touch with add2.

The output can be shifted by a controllable ground offset, and can also be clipped to a

specified maximum voltage. These voltages can be modified during a test without halting the

waveform being generated. Details can be found here.

LVTestApplication.pdf

LVTestApplication.chm

J001451%20V1.6.0%20-%20LVTGO-VBS%20-%20Specification%20Sheet.pdf



There is also a powerful scripting mechanism by which repetitious operations in the GUI can

be automated. This is currently being extended to cover all the control features of the GUI

which are important for unattended running. See the chapter on the COM Scripting Interface

for additional details and further references.



1 Conventions in this document

Names in Bold Italics denote user controls labelled with that name, in an application form or

other parts of the Windows interface. This is also used for labels on parts of the LVTGO-

VBS unit itself.

The names of buttons and hot-spots are given in [Square Brackets].

A pipe (|) character is used to separate successive stages in navigating a GUI. For instance,

many applications have a Paste operation which can be reached with Edit | Paste.

2 Overview

The Low Voltage Test Suite is most commonly used as a way of generating a sequence of

test waveforms with repeatable pseudo-random settings. However, this is not the only way to

drive it, and it has several other capabilities.

In addition to the built-in waveform generator, the LVTGO-VBS unit’s outputs can be

specified directly with analogue inputs (effectively using the unit as a signal amplifier with

low output impedance) or with CAN messages. This is most useful when reproducing a

waveform programmatically using the COM scripting interface.

The LVT can be made to defer playing a cycle until a trigger is received. The mechanism

provides not only for internally-generated CAN triggers (used for the Ramp Up and Down

waveform, and also used by the COM scripting interface) but also for user triggers, which

can be sent as analogue signals into the LVTGO-VBS unit or as user-configured CAN

messages. User CAN triggers are sent over a separate CAN bus to avoid potential clashes

with the CAN IDs used by the application interface. Both level-sensitive and edge-sensitive

triggers are possible, allowing both immediate control at the moment when the cycle is due to

begin and a produce/consumer relationship in which triggers can be sent in advance.

Triggers can also be emitted. These include user-configured CAN triggers (again, emitted

over the separate CAN bus) and two different approaches to analogue triggers, as simple

pulses or separately-configured edges. These can be anchored to different stages during

waveform generation.

A considerable amount of diagnostic information is available from the LVTGO-VBS unit,

some of it available over the analogue outputs (see the LVTGO-VBS Specification Sheet for

more details), but mostly over CAN. This includes the target (intended) output voltages, the

actually read output voltages, the current passed, the fan speed, and the temperature at the

internal heat-sink. Most of this information is available through the Miscellaneous Settings

form, or other forms reached from it.

Errors in the CAN communication or in the content of CAN messages received by the LVT

are reported. Trip states (such as over-temperature) to which the LVT responds by driving its

outputs to zero are both reported and logged. The log can be inspected and cleared.

Additional information is available for troubleshooting. This includes the version

information here, and the Special Values interface for inspecting the LVT’s internal state. It

is helpful if the version information is included in any bug reports. The Special Values

interface is a very low-level interface which is not directly useful to users, but add2 may ask

users to use it to diagnose problems.




3 Hardware

The LVTGO-VBS unit connections should be as follows:

Figure 1 – Connecting up the low voltage test hardware

The key aspects to the wiring are:

Ensure the power supply can provide more than enough current for the system you are

testing without poor transient behaviour.

Ensure all cables are rated for 70A or more if you are expecting to use full loading

currents.

If you are not using the ground offset connection, connect a heavy-duty cable between

the rear 0V and the offset ground pin (See figure 1). Full details for all LVT variants

are in the next section.

Warning: Excessive supply voltages will damage the LVTGO-VBS unit. It is strongly

recommended that they be only just high enough for the intended maximum output voltage.

In no case should they exceed 23.5V on a 20V unit, or 33.0V on a 30V unit.

3.1 [Hardware] The LVTGO-VBS Ground Terminals

There are three main types of LVTGO-VBS enclosure, with the terminals arranged

differently, and with slightly different labelling. The following description is not intended to

be complete, but only to clarify the location and labelling of the ground terminals. Because

the LVTGO-VBS can add a ground offset to its outputs, it is important to distinguish between

the input ground and the (potentially) offset output ground. Please see the LVTGO-VBS

Specification Sheet for full details of all the connections.





3.1.1 [Hardware] Small Units

The small free-standing enclosure has its input terminals at the back, at the top left of the unit

as seen from the back, above the 15-pin D-Sub connector labelled I/O Connection A. They

are side by side: one labelled VB IN, with a red knob, in the corner, and one labelled GND

IN, with a black knob, to the right of it. The output terminals are at the front, at the top right

of the unit as seen from the front, above the STATUS and TRIP LEDs. They are one above

the other: one labelled VB OUT, with a red knob, in the corner, and one labelled GND OUT,

with a black knob, below it. The ground supply terminal for the device under test depends on

the use of a ground-offset. Use the GND IN terminal for greater stability if you want no

ground offset; for a non-zero ground offset, use the GND OUT terminal.

If a small unit is supplied with BCD outputs, the additional C and D outputs are brought out

on the rear panel, above the power LED. The input connectors are unchanged.

T



3.1.2 [Hardware] Mid-Sized Units

Larger free-standing versions of the LVT exist. These support additional functionality (e.g,,

Micro-Cutouts waveforms), and may be fitted with additional outputs. The additional outputs

are brought out at the front. The right-hand side of the rear panel is almost exactly like the

rear panel of a single-output small unit, and the front panel is almost exactly like the left-hand

part of the front panel of a rack-sized unit without an integral power supply, so they are not

described further here.

3.1.3 [Hardware] Rack-Mounted Units

The two other variants are large enclosures designed for mounting in a rack. The picture

above shows the left-hand end of the front panel. Not all the outputs may be fitted. If there is

a single positive output, it is the VOUT (D) output at the top left on a red base.

The two RJ45 connectors (CAN and RS485) and the I/O Connection A connector are still at

the back, now at the lower right-hand corner seen from the back. Both of them use screw

terminals with plastic bases, black for ground terminals and red for the others. Seen from the

front, the main output connectors are at the top left. In the corner is a terminal with a red

base, labelled VOUT (D). Below it is a terminal with a black base, labelled VGND (0V). To the

right of the VGND (0V) terminal, on the other side of the fan, and nearer the base of the unit, is a

terminal labelled VGND OFFSET. Use the VGND (0V) terminal for greater stability if you want no

ground offset; for a non-zero ground offset, use the VGND OFFSET terminal.



One variant uses the same input terminals as the small free-standing enclosure, except that in

the larger box they are not in the corner of the box but nearer the centre, labelled VIN for the

positive supply input and OV for the ground input. The other variant has an integral power

supply, fed with mains power from a normal IEC 3-pin connector at the back of the unit, near

the centre at the bottom. The outputs from the power-supply are fed directly internally to the

LVTGO-VBS, whose power input terminals are not accessible outside the enclosure.

However, the power-supply outputs are also fed to additional terminals at the front of the

unit, near the top and the centre, VPSU and VGND (0V). The two terminals labelled VGND (0V) are

equivalent.

To avoid laborious wording, the rest of this document refers to the terminals as they are

labelled on the small free-standing enclosure, with occasional references to the VGND (0V)

terminal.

See also the short section on the GO Feedback control for configuring the LVTGO-VBS unit.

The unit cannot infer from a zero ground-offset setting that the setting will remain zero, and

has no way to determine which terminal is actually being used to supply the device under

test. The associated configuration is the responsibility of the user. However, it is stored with

a waveform profile, and will be set accordingly whenever a profile is loaded. The profiles

supplied with the LVTest VISUALCONNX Application already include appropriate settings.



4 Software

4.1 [Software]: Load the LVTest Application

Run the LVTest application for VISUALCONNX from the start menu:

START | All Programs | add2 | LVTest VCX Project V6 | LVTest 6

VISUALCONNX will proceed to load all the Forms and Scripts and the LV Test connection

to allow communications over the CAN port. This may take a few seconds.

4.2 [Software]: Run the LVTest Application

The window first appears looking like this:

The text in the window invites you to Press the Run button on the toolbar.

Press the [Run] icon in the task-bar to start communications with the LVTGO-VBS firmware

and start monitoring the waveforms. All forms except the Low Voltage Test Suite Main

Menu will disappear.



While the application connects, the text in the window shows as Connecting…

If the application is unable to communicate with the LVTGO-VBS, or communication is

interrupted, the following screen will be shown. If communication is resumed the connection

will be re-initialised.



Successful connection to the LVTGO-VBS will bring up the Main Menu.

Exported%20from%20Word/Use%20for%20CHM/Waveform_Main



5 The Main Menu

From this form you can choose one of the following waveform types by clicking on its

button:

Extremely Fast Transient Burst Noise

Random Cranking

Ramp Up and Down

Constant Voltage

Alternative Ramp

Captured Waveforms

Micro-Cutouts

5.1 [Menu]: View the application help document

Clicking on the [Help] hot-spot at the top right of the form brings up a WindowsTM

Help

document for the application.

5.2 [Menu]: The tab-bar

The tab-bar is present for consistency with the other forms. It shows only this (disabled) tab.



5.3 [Menu]: Selecting and using a Waveform

For each waveform type, first select the Waveform type by clicking on one of the buttons in

the column down the left, and then click the [Configure and Run Test] button. You will

notice that the [Configure and Run Test] button shows momentarily RED when you choose

a waveform type, to remind you to use that button next.

Normal state

Prompting state after selecting waveform type

This configures the application software to play the selected waveform type, brings up the

Waveform Main form, and causes the last-used profile for that waveform type to be reloaded.

There are two editable controls below the diagram of the selected waveform type. See the

Settings and Randomisation chapter for detailed instructions on modifying their contents. It

is best and easiest to change these, if you wish to change them, before selecting the waveform

type.

The Main Readback Interval (ms) should be short enough to capture the main features of the

waveform. This is normally most important for rapid EFTBN cycles. However, a very short

readback interval (such as 1ms) will use a considerable fraction of the available CAN

bandwidth, and on lower-performance PCs it may supply data faster than they can be

processed by the application.

The Graph Read Interval (ms) is less critical. It controls the frequency with which

information from the LVT is updated. Making it quite short will ensure that visible values

(e.g., in strip-charts) are updated promptly.

The large picture occupying the lower part of the form gives a preview of the waveform type.

Initially it shows a Random Cranking waveform; selecting another waveform type brings up

the appropriate picture.



Overlaid on the waveform-type diagram are the version numbers of the GUI at the lower left-

hand corner, and the version number of the firmware at the lower right-hand corner.

The Stop Button at the lower right of the form is used to exit the application. It prompts the

user to confirm the exit with the following dialogue-box:

Selecting [No] dismisses the message box, and the user is returned to the Main Menu.

Selecting [Yes] stops the application and disconnects from the Low Voltage Tester.

Disconnecting will not interrupt the LVT while it is playing a waveform. Waveforms using

the Configuration Trigger (such as the Ramp Up and Down waveform) will not continue

beyond the end of the present cycle unless the trigger is supplied (over the Host CAN bus)

from some other source.



6 The Waveform Main form

This form is initially reached from the Main Menu by clicking on the buttons [Waveform A],

[Waveform B], [Waveform C], [Waveform D], [Free Ramp] or [Captured Waveforms].

Most other forms allow a direct return to this form, configured for the currently-chosen

waveform type, using a tab at the left-hand end of their tab-bars.

The heading shows the currently selected waveform type, but otherwise it is common to all

the different waveform types. Depending on the waveform type, some controls may be

hidden or disabled. It is recommended that the user read this chapter, and the chapters on

Voltage Configurations, Timing and Frequency Configurations and Settings and

Randomisation, before the waveform-specific chapters.

Options available from this form:

Return to the main menu

Save the current settings as a profile

View the application help document

Use the tab-bar to bring up other forms

Load settings from a profile

Choose which cycles to play

Run, pause and stop a waveform

Monitor progress while running a waveform

Control logging

Monitor the values of parameters as they are calculated

Monitor a selected HIL analogue input



6.1 [Main]: Returning to the main menu

Clicking on the [Home] hot-spot at the top left of the form returns to the Main Menu.

6.2 [Main]: Save the current settings

Modified settings can be saved to the currently selected profile by clicking on the [Save] hot-

spot near the top left of the form. If saving fails (perhaps because the profile is read-only),

use the following control instead.

Clicking on the [Save As...] hot-spot just to the right of the [Save] hot-spot allows you to save

the current profile to a different file. If the profile is saved successfully, it will become the

currently-selected profile.

If the profile already exists, you will be asked whether you wish to over-write its contents,

choose another file, or cancel the operation. If writing to the file fails (perhaps because it is

read-only) you will be given the chance to choose another file, or cancel the operation.

6.3 [Main]: Viewing the application help document


Help




6.4 [Main]: The tab-bar

Below the title and the row of hot-spots is a tab-bar. The tabs in it can be clicked to bring up

other forms. The tab-bar for this form exists in three versions, depending on the currently-

selected waveform type.

Most waveform types use the tab-bar above.

Captured waveforms use this tab-bar. There are no settable parameters of the kind used for

other waveforms, and the Timing and Frequency Configurations form has very limited use

(only the Output Filter control). The [T Settings] and the [Param. Graphing] tabs are

replaced with more relevant forms (which are only used for Captured waveforms). The

Voltage Configurations form is still available because it gives access to some additional

voltage settings. See Additional Voltage Parameters on the Voltage Configurations form. If

you need the Output Filter control, it can still be reached by clicking on the [U Settings] tab

to bring up the Voltage Configurations form, then on the [T Settings] tab on that form.

Clicking on the [U Settings] tab in the tab-bar brings up the Voltage Configurations form.

Clicking on the [T Settings] tab in the tab-bar brings up the Timing and Frequency

Configurations form.

If the currently-selected waveform type is Captured Waveform, the Captured Import tab

following is shown instead.

Clicking on the [Captured Import] tab in the tab-bar brings up the Captured Import form.

This tab is shown only if the currently-selected waveform type is Captured Waveform:

otherwise the [T Settings] tab is shown instead.

Clicking on the [Param. Graphing] tab in the tab-bar brings up the Parameter Monitoring

form.

This tab is not shown if the currently-selected waveform type is Captured Waveform. The

Captured Transfer tab ifollowing s shown instead.

Clicking on the [Captured Transfer] tab in the tab-bar brings up the Captured Transfer form.

This tab is only shown if the currently-selected waveform type is Captured Waveform;

otherwise the [Param. Graphing] tab preceding is shown instead.



Clicking on the [Misc. Settings] tab in the tab-bar brings up the Miscellaneous Settings form.

This form gives access to some other special forms: Error Status and Special Values, Trip

Status, and HIL Inputs.

Clicking on the [Triggering] tab in the tab-bar brings up the Input Trigger Configuration

form. From there a tab can be used to go to the Output Trigger Configuration form.

6.5 [Main]: Loading waveform settings from profiles

The settings that define a specific waveform are collectively called “profiles” Profiles are

saved as files with the suffix .prw . The long Waveform Profile control shows the currently

used profile. Each waveform type has an associated (most recently used) profile. Initially

this is a default profile, called Default.prw. If the most recently-used profile cannot be

loaded, a warning is issued and the user is prompted to choose a different profile.

To load a different pre-defined waveform, you can edit the path in the [Waveform Profile]

property control

or browse for it by clicking on the

open-dialogue button at the right-hand end of the editable area

It is possible to edit the path directly in the control, but this is not recommended as a way to

create a new profile. If a profile with this name exists already it will be loaded, and the

current settings will be lost. In any case, the new profile must be saved after the name has

been specified. If you wish to create a new profile it is better to use the Save As... hot-spot.

When a profile has actually been loaded, its path

and file-name appear in grey below the editable text of the control.

If the profile appears to have been saved for a different waveform type, you will be warned

before opening it. If you open it anyway and then save it later, it will be saved with the

currently-selected waveform type. Clicking on the Open button or pressing Enter will import

the settings from the file and re-configure the waveform settings on the LVTGO-VBS unit.



6.6 [Main]: Modifying the parameters that define the waveform

These settings may then updated by editing them (if modified, they show up with a coloured

background) and then committing to the modified value by pressing the Enter key, at which

point the background becomes white again. Moving the focus to a different control without

pressing Enter abandons any changes and the field reverts to the previous value. Clicking on

the [Save] hot-spot or the [Save As…] hot-spot saves ALL settings (Time, Voltage, Cycles

etc.) associated with the currently loaded waveform.

For details of the randomisation options, see the Settings and Randomisation chapter.

6.7 [Main]: Running waveforms

6.7.1 [Main]: Playing from and to a specified cycle

You can choose to run the test waveform for a given number of “cycles” or seconds.

Each waveform is defined as a succession of defined steps. A “cycle” is a complete run

through all the steps of the current waveform in turn. The first step T0 is only included as part

of the first cycle (numbered 1). Subsequent cycles start with step T1. The number of cycles

can be up to (224

- 1) . As a special case, if the number of cycles is given as 0 then there is

no upper limit and the waveform will be repeated until externally stopped.

Alternatively, the length of time playing can be specified in seconds, up to (224

– 1) (that is,

16,777,215 seconds, or a little over six months). Time spent in the very first cycle in time-

step T0 is not counted, nor is time spent calculating cycles which are not played, nor time

spent checking voltages for random cranking waveforms before the cycle begins. However,

time spent in a cycle which is cut short with [Stop] and then resumed with [Play] is counted

towards the total. The main use of this option is to control high-speed EFTBN waveforms

where the cycle lengths are characteristically very short but also very irregular. These are

normally run for a specified length of time after an initial sustained voltage, without being

interrupted in the course of the configured interval.

If any of the waveform parameters are randomised, it can be useful to re-start a sequence

from a specified cycle iteration, rather than from the first cycle. The waveform will then be

calculated from the first cycle, but without being “played” - that is, it does not drive the

outputs and it does not wait for any time-periods to complete - until the specified cycle is

reached.

The tick-box in the Start Cycle control toggles it between the two states shown above.



When the box is not ticked, the Start Cycle is 0, and playing begins with time step T0 of the

first cycle. If the box is ticked, a Start Cycle number can be entered into the box, and the

previous cycles will only be calculated, without driving the LVT outputs. If the number is 1,

then playing begins with the first cycle, but with time-step T0 omitted.

If the Time Option is specified as a (non-zero) count of cycles, then it includes any cycles

calculated but not played. If the Start Cycle is greater than the number of cycles, then the

LVTGO-VBS unit will stop without driving any cycle to the output.

6.7.2 [Main]: Starting, Pausing, Resuming and Stopping

You can select the waveform play mode from these buttons:

Play Button

Initially, and after a Reset, the [Play] button plays from the specified Start Cycle until the

specified Time Option has elapsed. If an input trigger is configured, they will be required to

start the first cycle. This was not reliably true in versions of the firmware previous to V3.0.0.

More precisely, the waveform is calculated from the beginning of Cycle 1 until the beginning

of the specified Start Cycle. When the Start Cycle is reached, a clock is started and the

waveform is used to drive the outputs. When the waveform has played for the specified

number of seconds on the clock, or the specified number of cycles has been finished, the

clock is stopped and the output load voltage is driven to the “Voltage after Test” value.

Attempting to play for a number of cycles less than the Start Cycle will go immediately from

calculating the initial cycles to the “Voltage after Test” without playing any waveform.

An unspecified Start Cycle is equivalent to a Start Cycle set to 0, which inserts at the

beginning of Cycle 1 (only) an initial step in which it drives voltage U0 for time T0.

A zero Time Option (play for 0 seconds or for 0 cycles) is used to specify playing

indefinitely. Changes to the Start Cycle have no effect while a waveform is playing.

If a waveform is already being Played, the [Play] button has no effect.

If the waveform is currently Paused, the [Play] button resumes playing the waveform from

the point where it was interrupted, with the clock running. If the waveform is Stopped, the

waveform is played from tbe beginning of the cycle being played when it was interrupted.

This also sets the clock running. However, the time is not set back to the time at the

beginning of the current cycle. Starting with Version 3.0.0 of the firmware, if an input trigger

is configured, it will be required to re-start a cycle after Stop. This does not apply to resuming

a Paused waveform.

Current play mode LED

This LED is positioned between the [Pause] and [Play] buttons, to the left of the Trip LED,

and will only light when the waveform is playing. It does not distinguish, however, between

calculating waveforms before the Start Cycle, actually playing waveforms to the output, and

waiting after the specified Time Option has run out.



Trip LED

This LED is also positioned between the [Pause] and [Play] buttons, to the right of the Play

LED. If the LVTGO-VBS unit is in a trip state, this is reported on the Trip Status form. This

is accompanied by flashing the TRIP LED at the front of the unit, and sounding a buzzer. For

convenience in noisy environments, or if running the unit remotely, this control lights up in

red if the LVTGO-VBS unit is tripping.

See the Trip Status form for more details.

Pause Button

The [Pause] button temporarily stops the waveform (with the option of resuming from the

current point). This has no effect if the waveform is not being played. The clock is stopped

while the waveform is paused, and the current output voltage is sustained. The current time-

step does not time out, and a configured amount of time spent playing will not be consumed.

Click on the [Play] button to resume.

Stop Button

The [Stop] button stops playing the current cycle and the output voltage is driven to the

“Voltage after Test” setting. This has no effect if the waveform is not being played. The

clock is stopped when the waveform is stopped. Clicking on the [Play] button re-starts at the

beginning of the current cycle. If playing for a configured amount of time, any time spent re-

playing the beginning of the current cycle will be lost. That is, although no time is lost while

the clock is stopped, returning to the beginning of the current cycle does not reset the elapsed

time to the time when it was first reached.

Reset Button

The [Reset] button stops any current waveform from playing, sets the current cycle to 0,

resets the clock, and drives the output to “Voltage after Test”.

6.8 [Main]: Inspecting and logging progress and outputs from the

LVT

Some fields on this form show information reported from the LVTGO-VBS unit, and are not

modifiable by the user (though the user can alter the display settings for the strip-chart).



To the right of the cycle-count controls are two informational fields which show the current

progress through a sequence of cycles.

Current Cycle – shows the current cycle number (or the next cycle number if waiting to

begin a new cycle). This is updated even while calculating cycles earlier than the Start Cycle,

which are not “played”.

Current Step – shows the current time-step in the current cycle, or special states like

“stopped” or “waiting for a trigger” if no waveform is playing. This field will be hidden if the

current step is not being usefully updated. This will be true if the Auto-Cycle Type control

on the the Miscellaneous Settings form is set to send a frame for every new cycle.

Progress Bar

A more immediate indication of progress through a specified number of cycles is given by

the Progress Bar control beneath the controls just listed. It does not appear if the number of

cycles to play is set to 0 (unlimited). It shows the proportion of completed cycles. It is not

used when playing a specified number of seconds, as elapsed time as such is not reported

from the LVTGO-VBS unit, and “dead reckoning” time may be distorted by paused states

and time spent in the first cycle in time-step T0, which is not counted towards the number of

seconds configured.

The lower left-hand part of the Waveform Main form is taken up with a strip-chart which

shows a scrolling display of the calculated VBatt output voltage. This is not the actual

measured output voltage, which can be found on the Miscellaneous Settings form.

Two additional displays are in the right-hand margin to the right of the main output strip-

chart.



The Parameters display shows the current value of the T, U and F parameters used in the

most recently completed wave-form. Unknown or unused parameters (e.g., T3 in a Random

Cranking waveform, T0 if not playing the first cycle) are shown as blanks. This display will

not be updated usefully if the current waveform type is Constant Voltage or Captured

Waveform, or if parameter streaming is disabled.

The HIL Readings display shows the currently selected HIL input voltage, if any, and the

interpretation (high or low, after debouncing) made by the LVTGO-VBS. The signals are all

“asserted high”, so a high value is T for True and a low value is F for false. This is for

debugging analogue inputs which can optionally be used as switches. See Selecting the HIL

input to show on the Waveform Main form on the HIL Inputs form. The fields will show as

'-' if the associated information is not currently being updated.



6.8.1 [Main]: Logging data from the LVT

To the right of the strip-chart are a set of radio buttons, a text-box and two tick-boxes which

control logging options. These are disabled when there is a current data log (the options used

cannot be changed in the middle of a log).

The Log Option control is used to select whether you wish to log no voltage data, just the

target voltage as shown on the strip-chart on this form, or the target voltage together with all

the other readbacks shown on the Miscellaneous Settings form.

The Compress tick-box can be ticked this box when logging voltage data (i.e., not Log

Option set to None), to save space on your hard disk. Wave data generally compresses well.

The additional readback data typically has enough noise not to compress well without loss.

Lossy compression is available, and controlled from the Logging compression controls on the

Miscellaneous Settings form.

The Log Params tick-box can be ticked if you wish to log all parameters. Parameter logs are

always compressed. Parameters can only be logged when they are streamed (see Controlling

Parameter Streaming on the Parameter Monitoring form). Parameters are not streamed for

Constant Voltage or Captured Waveform waveforms, and usually are not streamed for very

fast EFTBN waveforms.

If Captured Waveform has been selected as the waveform type, there are no parameters to

display, and this tick-box is not displayed. Instead, a Waveform Number selection control

and a button to show a preview of the waveform are shown. See Selecting and previewing

captured waveforms for more details.



This control specifies a number of seconds during which a log will continue to be recorded

while waveform generation is stopped. The timer is started when the LVTGO-VBS unit

reports its state as Stopped (e.g., because the requested number of cycles has been played),

and when the user clicks on the [Stop] or [Reset] buttons. The timer is stopped (and, if

necessary, the log is re-started) if the unit reports a state other than Stopped, and the user

clicks on the [Play] button. The timer is also stopped, and the log stops, if the user clicks on

the following [Save/Clear Logged] Data button. Times shorter than 10 seconds are not

allowed. The actual additional time spent logging may be up to 5 seconds longer than the

time configured.

The [Save/Clear Logged Data] button is below the other logging controls, to the right of the

lower right-hand corner of the strip-chart.

It is enabled only when there is data in the current log. It clears the current log, but gives the

user a chance to save to a file first. The file is given a name which reflects the form being

saved and the current date and time. Once the data have been cleared, the other logging

controls are re-enabled.

6.9 [Main]: Selecting a specific Captured Waveform

An additional control is available when the currently-selected waveform type is Captured

Waveform. It appears above the Data Logging controls and to the right of the [Reset] button.

The Waveform Number selection control is used to select the index (from 1 to 64 inclusive)

of a captured waveform as stored on the LVTGO-VBS unit. If the application has been

synchronised with the unit, additional information will be available in the Captured Transfer

form. The Target list on this form shows the index numbers of stored waveforms alongside

their descriptive text.



6.10 [Main]: Pre-viewing Captured and Micro-Cutouts Waveforms

These controls are only visible when Captured Waveforms or Micro-Cutouts waveforms are

selected.

If the Show Preview tick-box is ticked, the main strip-chart is made narrower, and the extra

space used to show a strip-chart preview of the waveform. For a Captured Waveform, if

there is no waveform of that index stored in the LVTGO-VBS unit, or the application has not

been synchronised with the unit, the preview will be blank.

With a selected Captured waveform, after

synchronisation

With no waveform selected

.



7 The Voltage Configurations form

This form appears when one of the [U Settings] tabs is clicked. These exists in the tab-bars

of the Waveform Main form here, and the Timing and Frequency Configurations form here.

It allows the voltage parameters of the current waveform to be inspected and modified.

Constant Voltage waveforms and Captured Waveforms use (and display) only a very limited

set of the available controls.

The pink area marks a control set to 16V, which is greater than the limiting voltage 15V set

in the Max Output Voltage control.

7.1 [Voltage]: Return to the previous form

Clicking on the [Back] hot-spot at the top left of the form hides this form, and returns to the

previously visible form. Settings are not lost when the form is hidden.

7.2 [Voltage]: Save the current settings

If the currently-selected waveform type is Random Cranking, and current voltage settings

violate the Voltage constraints for Random Cranking, then a warning is issued if you try to

save them to a profile.



Clicking on the [Save] hot-spot below the [Back] hot-spot saves the current settings (not just

the voltage settings) to the currently-selected profile.

To save to a different profile, use the [Save As…] hot-spot. If the profile is saved

successfully, it will become the currently-selected profile.

7.3 [Voltage]: Viewing the application help document


Help


7.4 [Voltage]: The tab-bar


other forms. The tab-bar for this form exists in two versions, depending on the currently-


Most waveform types use the tab-bar above.

Constant Voltage and Captured waveforms use the tab-bar above. There are no T Settings

parameters for these waveform types.

Clicking on the [Waveform Main] tab in the tab-bar brings up the Waveform Main form.



navigate to the Waveform Main form.



Clicking on the [T Settings] tab in the tab-bar brings up the Timing and Frequency




navigate to the Timing and Frequency Configurations form.

7.5 [Voltage]: Enabling A, B and C outputs in a Random Cranking

waveform

An additional control is available when the currently-selected waveform type is Random

Cranking and the currently-connected LVTGO-VBS unit reports itself as having an ABCD

daughter-board. It appears below the left-hand end of the tab-bar.

The ABC Enable tick-box, when visible, controls whether the A, B and C outputs required by

the Ford CI230 test waveform are generated or not. The state of this control (whether visible

or not) is loaded from the current profile.

7.6 [Voltage]: The number of EFTBN Steps

An additional control is available when the currently-selected waveform type is Extremely

Fast Transient Burst Noise. It appears below the left-hand end of the tab-bar.

The Number of EFTBN Steps control, when visible, controls the number of steps in an

EFTBN waveform. See Setting the number of steps for more details.

Only values from 2 to 8 are accepted.

Changing this value has the effect of a Reset.

7.7 [Voltage]: Voltages defining the waveform



The U Parameter controls fill the upper part of the form below the tab-bar. There is a line of

controls for each voltage parameter Un used for the current waveform. See Settings and

Randomisation for details of the randomisation settings. The choices of random distribution

and seed value are discrete (from pull-down menus). The other values range from 0V to 30V

in steps of 1mV. The minimum, maximum and mean may not be given values greater than

the Max Output Voltage. If it is really intended to randomise over a larger range and clip the

output, set the Max Output Voltage to 30V at first (or to 20V if that is the maximum voltage

for the unit), and to the intended limiting value after the other settings are defined. Voltage

settings on the form above the current Max Output Voltage are shown in a distinctive colour.

The U0 value will only be calculated once (if at all), for the beginning of the first cycle. In

the case of a Constant Voltage waveform, that is literally all the parameter calculation that

happens. This means that U0 values are only randomised in a very weak sense.

For a Captured Waveform, there are no U parameters at all. The voltages are entirely defined

by the stored waveform data.

Changes to these settings made while a cycle is playing will not take effect until the next

following cycle. However, changes to seed values will not take effect until the next reset.

Further details specific to each type of wave-form can be found at

EFTBN waveform

Random Cranking waveform (see also here)

Ramp Up and Down waveform

Constant Voltage waveform

Alternative Ramp waveform

Captured waveforms

Micro-Cutouts (see also here)

7.8 [Voltage]: Voltage Instability while Loading Profiles

Whenever a profile is loaded, which happens whenever the currently-selected waveform type

is changed, there is no guarantee of the order in which the parameters defining the waveform

are updated. Normally loading a profile will force the waveform to stop, and the voltage-

after-test voltage will be driven (subject to the current maximum voltage). However, these

voltages may be updated in either order, and the interval between these two updates may be

considerable. In addition, the voltage-after-test value is derived from different parameters

when using Micro-Cutouts waveforms, which can produce updating in a different order, and

with significantly different effects. In particular, the voltage may briefly “spike” to a value

above both the old and the new maximum voltages, though efforts are made to minimise this..

If equipment is sensitive to spikes or dips in its input voltage, it is best to disconnect it while

loading a profile.

7.9 [Voltage]: Special constraints for random cranking waveforms

For a Random Cranking waveform only, special constraints are applied to the voltages.



If the user attempts to navigate away from the form using a hot-spot or a tab in the tab-bar, or

attempts to save the current settings, a message-box appears warning the user about possible

violations of the constraints, and giving the opportunity to adjust the settings before

continuing.

For further details, see Voltage constraints for Random Cranking.

7.10 [Voltage]: Additional voltage parameters

Below the array of U Setting parameters (if any) is a row of controls which set voltages

applicable to the entire waveform. These are the only voltage controls which apply to

Captured Waveforms.

The Max Output Voltage control sets the maximum output voltage, up to 30V in steps of

1mV. If the attached LVTGO-VBS unit is a 20V unit, or its output range is undetermined,

then the voltage limit will be constrained to be no more than 20V. You will not be allowed to

set a voltage control so its value can be higher than this. However, it is possible to set the

maximum output voltage to its maximum (20V or 30V, depending on the LVTGO-VBS unit

attached), set the other voltage controls freely within that limit, and then vary the maximum

output voltage freely as the waveform is played. Any voltages displayed which are currently

greater than this limit are displayed with a distinctive background colour.

The maximum output voltage is loaded from the current profile. No profile currently

supplied by add2 has a maximum output voltage higher than 20V. However, you are free to

save profiles with a higher limit if the currently-attached LVTGO-VBS unit supports it.

Warning: if the currently-attached LVTGO-VBS unit supports only 20V output, then this

control will be limited to 20V. Saving a profile in this state may change the maximum output

voltage stored for it. Attaching a 30V unit and re-loading the profile will not restore the old

maximum voltage setting. However, it should be possible to re-set just this setting and save

the profile again.

Fast Output is normally selected. When selected, a falling output voltage will driven low by

controlled leakage to ground. When clear, the output voltages may fall more slowly,

depending on the load characteristics.

Voltage After Test is the output voltage (not including the ground offset) used when a

waveform is stopped (before running, after running a prescribed number of cycles, and after

[Stop] or [Reset]). This is not used when the waveform is paused, when the current output

voltage is sustained without change. This is one of the voltage controls which cannot be set

to a value higher than the current limit on the Max Output Voltage control.



This control is disabled when Micro-Cutouts waveforms are selected. The voltage used

during the T1 and T3 steps, and the voltage used when not paused and not playing a cycle, is

the higher of the available voltages (Low U + Pulse), but limited by the maximum output

voltage.

There may be brief voltage spikes (less than 1 ms) when moving from a different waveform

type to Micro-Cutouts waveforms, because the previous voltage-after-test voltage will be

sustained even after the high voltage (Low U + Pulse) begins. If this is a problem, the device

under test should be disconnected while selecting Micro-Cutouts waveforms. Similarly, there

may be a short voltage dip when moving from Micro-Cutouts waveforms to a different

waveform type, as the Pulse will be switched off before the new waveform’s voltage-after-

test setting is applied.

Ground Offset sets a controllable ground offset. This can be changed freely while a

waveform is running. All output voltages (including the Max Output Voltage) are offset by

the Ground Offset value. However, 20V units will under no circumstances drive more than

20V. 30V units will operate up to an absolute maximum of 32.5, specifying an output

voltage of 30V and a ground offset of 2.5V. The ground offset can be set to any non-negative

voltage up to 2.5V, in steps of 1mV. This does not mean that the output is controlled with

that precision. On 20V units, the smallest controllable change in the Ground Offset voltage

output is about 3mV; on 30V units the smallest steps of control are approximately 0.7 mV.

BNC Enable (when visible) will enable a BNC filter output on the LVTGO-VBS unit. This

will be applied continuously until switched off. The control will not be visible in the absence

of a daughter-board which supports the BNC filter in the LVTGO-VBS itself.

7.11 [Voltage]: Voltage Parameters for Micro-Cutouts

The following additional controls appear for Voltage Parameters

For Micro-Cutouts waveforms only, the voltage parameters U1 and U2 are treated specially.

U1 is labelled as Low U, and U2 is labelled as Pulse The intended voltage at the beginning

and end of the tests (for time intervals T1 and T3 respectively) is the sum of these voltages. In

between, the voltage oscillates between Low U and Low U + Pulse. This voltage is, as

always, limited by the current maximum output voltage and the physical limits of the

LVTGO unit. These voltages cannot be randomised. Changes to these values will not affect

the voltages used during a cycle until the next time a new cycle is begun, but the derived

voltage (equal to Low U + Pulse.) used as the voltage after test will reflect changes to these

two voltage parameters as soon as possible.



If parameters are being streamed (there is not much point at present), Low U is reported as U1

and Pulse is reported as U2.

Below the middle of the waveform diagram is a tick-box

An additional control specifies the polarity of the pulse. If the Pulse High tick-box is clear,

the pulses are low-going: that is, the voltage in between T1 and T3 is generally Low U +

Pulse, but pulses of the specified width (see Timing Parameters for Micro-Cutouts

waveforms) fall to Low U. If the tick-box is selected, the pulses are high-going: the voltage

in between T1 and T3 is generally Low U, but pulses of the specified width rise to Low U +

Pulse.

7.12 [Voltage]: The waveform diagram

The right-hand part of the form below the tab-bar shows schematically the waveform type,

and identifies the index numbers of the time and voltage settings which apply to the currently

selected waveform. For historical reasons, in a Random Cranking waveform the labelling of

the voltage values has no obvious relationship with the time-steps with which they are

associated.

7.13 [Voltage]: The help text

The lower part of the form shows a brief Help message.



8 The Timing and Frequency Configurations form

This form appears when one of the [T Settings] tabs is clicked. These exists in the tab-bars

of the Waveform Main form here, and the Voltage Configurations form here here. It allows

the time and (for Random Cranking waveforms) frequency parameters of the current

waveform to be inspected and modified. Constant Voltage waveforms and Captured

Waveforms only present the Output Filter control. For Captured Waveforms, there is not

enough space for a [T Settings] tab. If necessary, use the [U Settings] tab to bring up the

Voltage Configurations form first, and use the [T Settings] tab on that form.

8.1 [Time]: Return to the previous form


previously-displayed form. Settings are not lost when the form is hidden.

8.2 [Time]: Saving the settings

Clicking on the [Save] hot-spot to the right of the [Back] hot-spot saves the current settings

(not just the voltage settings) to the currently-selected profile.





8.3 [Time]: Viewing the application help document


Help


8.4 [Time]: The tab-bar


other forms.


Clicking on the [U Settings] tab in the tab-bar brings up the Voltage Configurations form.

8.5 [Time]: Times and frequencies defining the waveform

The T Parameter controls fill the upper part of the form below the tab-bar. There is a line of

controls for each Time parameter Tn used for the current waveform. Additionally, for a

Random Cranking waveform there are also two lines of F Parameter controls F0 and F1 for

the frequency of the sinusoid.



See Settings and Randomisation for details. The choices of random distribution and seed

value are discrete (from pull-down menus). The other settings range from 0s to 65.535s in

steps of 1ms, for the time values, and from 0 Hz to 250 Hz in units of 0.1Hz for the frequency

values.

Changes to these settings made while a cycle is playing will not take effect until the next

following cycle. However, changes to seed values will not take effect until the next reset.

8.5.1 [Main]: Timing Parameters for Micro-Cutouts waveforms

With Micro-Cutouts waveforms selected, some additional controls are available, and some

others have slightly modified behaviour.

There is no T0 step, and it cannot be configured. Only T1 and T3 are available in the usual

way. At present (V5.0.0 of the firmware) these cannot be randomised or scaled, though it is

intended to supply both features in later releases. T2 is used to specify the basic time interval

used for the pulse-train, in association with a scaling factor. This is the width of a pulse. The

usual scaling factors are not available. Instead, there is a choice as shown in the following

picture:

The range of multiples of this scaling factor available depends on the choice of unit. At

present (V5.0.0 of the firmware) the limits are

100ns: 10 - 16383

1us: 1 – 13107

1ms: 1 – 104

4ms: 1 – 104



Near the middle of the form are the main pulse-train shape controls:

The Gap Counts controls are used to characterise the shape of the pulse-train, in association

with the Pulse High tick-box on the Voltage Settings form. If the pulses are high (voltage

Low U + Pulse) then the gaps are low (Low U), and vice-versa.

At the end of the T1 time-step (at the high voltage Low U + Pulse) the first pulse begins, and

lasts for one time-interval. All pulses except the last are followed by a gap. The first gap

lasts for First Gap Count time-intervals. After all gaps except the last there is another pulse,

which again lasts for one time-interval, and then another gap. The width of the gap changes

by one time-interval at a time, increasing or decreasing as necessary, until it reaches the Last

Gap Count after the last pulse. However, at the point where the last gap would be expected to

start, the pulse-train stops, and the high voltage Low U + Pulse is sustained for the T3 time-

step instead.

If the First and Last Gap Counts are equal, then there is only one pulse, and there is no real

“gap” at all. Otherwise, the total number of pulses generated will be one greater than the

absolute difference between the First Gap Count and the Last Gap Count. If the Last Gap

Count is greater than the First Gap Count, the gaps increase in size by one time-interval

(pulse-width) per pulse; if the First Gap Count is greater than the Last Gap Count, the gaps

increase in size by one time-interval per pulse.

If Pulse High is selected then the first pulse continues the high voltage of T1 and the last

voltage leads directly into the high voltage of T3, so the number of properly isolated pulses

with two distinct edges is reduced. As pathological cases, if just one pulse is generated then

the Low U voltage will not appear at all, and if two pulses are generated then the waveform is

effectively just a single low-going pulse whose width is First Gap Count time-intervals.

8.6 [Time]: Scaling the duration of time-steps

The column of tick-boxes headed “Scale” is used to support long time-steps. The effect of

placing a tick in the box is to bring up (in place of the Resolution text-box) a pull-down list of

multipliers. The selected multiplier is applied to all the time settings (minimum, maximum

and mean) for that row of controls. Un-ticking the box restores the Resolution settings. It is

not possible to set the Resolution to anything but the minimum value while using a multiplier.



The multiplier also affects the delay settings for output triggers, when these are anchored to

the end-points of the specified time-step. This is still true even if the trigger is delayed until

after the end of the specified time-step (this can only happen with positive delays after the

beginning of the step).

The last entry in the pull-down menu is x 0.5. This makes it possible to set time-steps which

are odd multiples of 0.5 ms. However, do not attempt to set the minimum length of a step to

less than 1 ms (that is, with a scale factor of 0.5, the nominal length of the time-step should

be at least 2 ms). If a time-step begins at an odd half-millisecond, the timing of output

triggers may be in error. The first time-step in the first cycle of a run always begins on a

millisecond boundary (in terms of the internal clock of the LVT), and for Random Cranking,

Ramp Up and Down and Alternative Ramp waveforms all cycles begin on a millisecond

boundary.

8.7 [Time]: EFTBN configuration

If an EFTBN waveform is selected, this form also shows a warning message referring the

user to the Voltage Configurations form to set the number of waveform steps.



8.8 [Time]: The waveform diagram

The right-hand part of the form below the tab-bar shows a graph which shows schematically

the waveform type, and identifies the index numbers of the timing settings which apply to the

currently selected waveform. This is especially important for the Random Cranking

waveform. For historical reasons the labelling of the voltage values has no obvious

relationship with the time-steps with which they are associated.

A Captured Waveform has only a single time-step, T1.

T0 is only used at the beginning of Cycle 1, and even then only if the Start Cycle is set to 0.

T3 is not used for a Random Cranking waveform Apart from this, the time-steps occur

consecutively in order from T1 up to the maximum used for the current waveform.

8.9 [Time]: The Help-text

The lower left part of the form shows a brief Help message.



8.10 [Time]: The Output Filter control

This control is often disabled, and will be shown like this.

If the LVTGO-VBS target has sufficiently recent firmware (at least 5.1.0) and has additional

output filtering options, it will be enabled like this:

In this case, the unit has a fast output stage, but this can be filtered down for smoother ramps,

or to meet specific requirements for slower edges. The filter times quoted are minimum

times between 10% and 90% of a requested voltage change. The ~0.5ms output filter is for

backward compatibility with older hardware. There may also be a lighter filter, with only

10 µs filter time. The ~0.5ms filter is not available for Micro-Cutouts and should not be

selected (the effect is actually to disable the 10 µs filter).

Auto is almost always a safe option. It uses the slowest available filter for waveforms

containing ramps, the fastest available filter for EFTBN waveforms and captured waveforms

with no interpolation, and the nearest filter available to 10 µs filter time for Micro-Cutouts.

[Misc]: The maximum-current controls

The Current(H) MAX display shows the maximum recorded load-circuit current, as taken

from the readings also sent to the strip-chart.

The [Clear] button to the right of this control is used to re-set the maximum to 0.



8.11 [Time]: Waveform-specific details

Further details specific to each type of wave-form can be found at

EFTBN waveform

Random Cranking waveform

Ramp Up and Down waveform

Constant Voltage waveforms have no timing or frequency parameters

Alternative Ramp waveform

Captured Waveforms have only an unmodifiable time-step T1

Micro-Cutouts waveform.



9 Settings and Randomisation

Where settings are selected from a menu, they take effect immediately. Settings which are

typed in by the user (e.g., voltages defining a waveform) usually follow a two-stage process.

When modified, they show up with a coloured background (the colour can be set as a

VISUALCONNX setting). The user can commit to the modified value by pressing the Enter

key, when the text background reverts to its normal colour (usually white). Moving the focus

to a different control without pressing Enter abandons any changes and the field reverts to the

previous value.

Timing, voltage and frequency settings may be randomised, where appropriate, to give a

repeatable but random based distribution of parameters. The controls which use

randomisation are on the Voltage Configurations and Timing and Frequency Configurations

forms (these also contain other controls). Frequency parameters are only used for a Random

Cranking waveform. These settings, exceptionally, will only take effect when the next cycle

begins (including the case where the LVTGO-VBS is stopped and is re-started from the

application). The seed settings are a further exception, as they only take effect when the

LVTGO-VBS is next started from a reset.

Captured waveforms have no numbered U or T settings. Each waveform has a single time-

step, T1, and its length is derived from the stored data. However, the global constraints

(maximum voltage, voltage after test, ground offset, and fast-output control) are still

available.

Micro-Cutouts waveforms have currently (Firmware V5.0.0) no support for randomisation,

and the only support for scaling is for the pulse-width, which is T2 scaled by the time-unit.

The present intention is to introduce scaling on the T1 and T3 time-steps, but not to allow the

“scale according to voltage difference” options or scaling by 0.5.

Each of the parameters is configured using a standard set of controls occupying one line of

the configuration form. The first control specifies the type of randomisation to be used (if

any). Controls with no effect on the current type of randomisation are hidden.

The following random distributions are available:



9.1 [Settings]: Fixed (no randomisation)

This only allows the actual voltage or time to be entered

9.2 [Settings]: Uniformly distributed

This allows the actual voltage or time to be randomised with a uniform distribution.

9.3 [Settings]: Normal distributions

These allow the actual voltage or time to be randomised with a normal distribution. The

mean of the distribution must be entered. There is a range of variances available (relative to

the square of the mean value): low, medium and high. Extreme values are clipped to the

specified minimum and maximum. The mean must not lie outside these values.



9.4 [Settings]: 1/x2 distribution

This allows the voltage or time parameter to be randomised with a 1/x2 distribution curve.

This is a uniform distribution in which the variates x are replaced with transformed variates

y = 1/x2: the distribution of x is restricted to values which keep y within range.

This distribution is designed to meet the requirements of the JaguarLandRover CI265 Test

Procedure for immunity to transients (Waveform A). A previous version of this distribution

which does not correspond exactly is still available, under the name Old 1/x^2. This is only

provided for backward compatibility with existing test specifications.

Do not set a minimum value of 0 for this distribution. Only zero values will be generated.

9.5 [Settings]: Random seeds

Each possible seed value starts the random-number generator used at a different point of its

cycle. For normal distributions the sequence has about 10^9 members; for the uniform and

exponential distributions there are 231

– 2 members. In practice the sequence is unlikely to

work through a complete cycle. Varying the seed is useful to cover a wider range of cases

over relatively short runs.

The seed values are not meant to be changed during a run. They will only be updated

internally in the LVTGO-VBS when they are initialised for Cycle 1 – that is, when starting to

play waveforms after a reset.



9.6 [Settings]: Resolution

It is possible to set a “resolution” for each randomised value, except for Time settings which

are scaled. Values resulting from the random-number generator will be rounded to a value

equal to the minimum value plus some integral multiple of the resolution (except for the

1/x^2 distribution, mentioned later). The value chosen will not exceed the maximum value,

but otherwise will be the nearest possible value meeting the constraints. Zero is permitted,

and gives the finest available resolution (1 ms for Time settings, 1 mV for Voltage settings,

0.1 Hz for Frequency settings).

This can affect the voltage constraints on random cranking.

Exceptionally, all values generated from the 1/x^2 distribution are multiples of the

resolution. These will not lie outside the range [Min, Max], but if the minimum is not a

multiple of the resolution the behaviour is different.

9.7 [Settings]: Scaling Time Settings

Timing parameters also have an option for scaling. This affects the minimum, maximum and

mean settings for that parameter. Choosing the scaling option forces the resolution to be the

minimum available resolution (1ms x the scaling factor chosen). To use scaling, tick the tick-

box at the right-hand end of the row of controls for the specified Time parameter, under the

Scale heading. This brings up a pull-down menu of the available scale factors, in place of the

text-box for specifying the resolution.

The pull-down menu also contains two special items at the beginning: U x 5 and U x 30.

These are used to implement ramps with special slopes prescribed by the JLR Test Procedure.

U x 5 gives a ramp of slope 5 s / V, and U x 30 gives a ramp of slope 30 s / V. If the time-

step is NOT a ramp, then these are equivalent to x 5 and x 10 respectively. U x 30 is NOT

equivalent to T x 30 for non-ramps. If these values are selected, and the time-step really is a

ramp, then the other control settings for this time-step are ignored. It is recommended that

these special settings not be used at all except for ramps.

Two special considerations should be noted. To ensure that output triggers can be configured

for any point in a (possibly very long) time-step, when an output trigger is configured to fire

at a specified offset from the end of a step, forwards from the start or backwards from the

end, the nominal offset is multiplied by the applicable scale factor.



Also, it is possible for one of the special U x 5 or U x 30 multipliers to be applied to a ramp

step where there is no voltage difference. This, uniquely, produces a zero-length time-step.

In fact, this is not achievable, and the nominal 0 ms time-step is actually 1ms long. This is

reflected in the values reported for the calculated parameter settings in the Waveform Main

form.



10 The Parameter Monitoring form

This form appears when the [Param. Graphing] tab is clicked on the tab-bar of the Waveform

Main form. It supplies the data for the Parameters display on that form, and is of limited use

in itself. However, up to two parameters may be chosen to be monitored on the strip-chart.

These values are updated when they arrive, and not at the end of the cycle (as happens on the

Parameters display). If any parameter has been chosen to be displayed, the low 16 bits of the

cycle number (wrapping round from 65,535 to 0) are displayed also.

10.1 [Parameters]: Return to the previous form


previously-displayed form.

10.2 [Parameters]: Viewing the application help document

Clicking on the [Help] hot-spot at the top left of the form brings up a WindowsTM

Help




10.3 [Parameters]: The tab-bar

Below the title and the row of hot-spots is a tab-bar. The single active tab in it can be clicked

to bring up the Waveform Main form


10.4 [Parameters]: Selecting parameters to inspect

The first row controls the choice of the first parameter to inspect (shown on the strip-chart

with a red line). The second row controls the second parameter to inspect (shown on the

strip-chart with a blue line). The first control chooses the type of the parameter (None,

Voltage, Time or Frequency). If the type is not None then the second control is visible, and

is used to select the index number.



10.5 [Parameters]: The main parameter values strip-chart

The main strip-chart shows the values of up to two selected parameters. These are the

calculated values after randomisation. This display shows the selected parameters in native

units (millivolts, milliseconds or decihertz), not scaled as in the Parameters display on the

Waveform Main form. It is updated more promptly than the Parameters display, which is

only updated at the end of a waveform cycle.

The legend at the left shows the pen-colours used for the data shown in the strip-chart.

10.6 [Parameters]: Controlling parameter streaming

This control can be used to control whether parameters are streamed. Normally they are

streamed. Suppressing streaming is only useful if cycles occur very rapidly (e.g., for a “rusty

file” test). If parameters are not streamed, the parameter display on the Waveform Main

form will be empty, and parameter logging will not be available. If parameters are already

being logged, this control is disabled.

Parameter streaming is not possible for Constant Voltage or Captured Waveform waveforms,

and the control is normally not available when playing these waveforms. As a special case,

the control is locked ”on” even for these waveforms if parameters are already being logged

for another waveform type and these waveforms are selected without stopping the log.

This control is available, and works, for Micro-Cutouts waveforms, but is not very useful. It

will be slightly more useful when the T1 and T3 time-steps can be scaled, and only important

if any of the voltage parameters come to be randomised. The present behaviour is to return

Low U as U1 and Pulse as U2. The time returned for T2 is the raw numerical U2 value, with

no adjustment for the selected time-unit.



11 The Input Trigger Configuration form

This form appears when the [Trigger Configuration] tab is clicked in the tab-bar of the

Waveform Main form. Access to the Output Trigger Configuration form is from the [Output

Triggers] tab in the tab-bar on this form. Input and output triggers are independent.

Significant incompatible changes to CAN input triggering have been introduced since

previous versions of the firmware and this application. If you have used CAN input triggers

in the past, please read this chapter carefully. See the section on Changes to the COM Input

trigger interface in the chapter on the Scripting using the COM interface for further

information.

Incompatible change from previous versions (new in V4.0.0 of the GUI)

The waveform is now always left waiting for a trigger when stopped. In particular, stopping

a particular cycle and then resuming at its beginning requires the same trigger (if any) as if

the playing proceeded from a previous cycle.

Only those controls relevant to the currently-chosen trigger options are enabled. In a few

cases, where different controls are displayed according to the currently-chosen trigger

options, none will be displayed if it does not apply. This picture shows a fairly full set, with a

user-configured CAN messages used as an input trigger.

11.1 [Input Triggers]: Return to the previous form





11.2 [Input Triggers]: Saving the settings


(not just the trigger settings) to the currently-selected profile.



11.3 [Input Triggers]: Viewing the application help document


Help


11.4 [Input Triggers]: The tab-bar

Below the title and the row of hot-spots is a tab-bar.


Clicking on the [Output Triggers] tab in the tab-bar brings up the Output Triggers form.

11.5 [Input Triggers]: Input triggers

At the beginning of each cycle actually played (not cycles merely calculated up to the

specified Start Cycle) the LVTGO-VBS unit will wait for an input trigger to be available.



If a trigger of the currently-configured type arrives and is detected on the LVTGO-VBS unit,

it is queued until the next cycle is ready to start, when a queued trigger will be consumed and

the next cycle will start playing. During this interval (which may be less than 1ms if the unit

is already ready to start the next waveform cycle) the trigger can be revoked (removed from

the queue).

There are several supported input trigger sources, and several supported input trigger modes

for interpreting them as trigger or revocation signals.

The Input Trigger frame displays all the settings for the currently-selected input trigger.

The Input Type option-group specifies whether input triggers are required, and if so what

type of trigger must be supplied..

None (free-run) means that the unit plays cycles without waiting for an external trigger. To

be precise, the unit is still triggered, but with a special internal trigger source which generates

triggers on demand. This explains the occasional appearance of Waiting for Trigger in the

Current Step display on the Waveform Main form, even when the input type here is None.

Analogue HIL Input means that the trigger is expected on the input HIL3 line (Pin 5 on the

15-pin I/O Connection A). Voltages above 2.5V are treated as line high, and voltages below

2.5V are treated as line low. The voltage is sampled every millisecond. Moreover, the line is

debounced so after a transition (in either direction) between line high and line low the line is

not sampled further for 100 ms. It is therefore possible for fast spikes on the line to produce

spurious trigger states (or not). See the LVTGO-VBS Specification Sheet for details.




The Input Analogue Mode option-group appears when Analogue HIL Input is selected.

The trigger mode can be level-sensitive or edge-sensitive. A level-sensitive trigger depends

only on the current line-high or line-low state (after debouncing). An edge-sensitive trigger

is set by transition between line-high and line-low going in the correct sense, and reset either

by an opposite-going edge or by actually being consumed to start a new waveform cycle,

whichever occurs earlier.

Target CAN message means that the message is received over the Target CAN bus.

Communication between the LVTest Application and the LVTGO-VBS unit normally uses

the Host CAN bus.

The Input CANID Type controls appear when Target CAN message is selected. They enable

the user to specify the CAN ID, whether it is a Standard or an Extended CAN ID, and the bit

number to inspect. If the CAN ID is small enough (less than 2048) to be either a Standard or

an Extended CAN ID, only the configured type will be recognised as a trigger message. If

the CAN ID is too large to be a Standard CAN ID, but a Standard CAN ID is configured,

the warning message ID too large is displayed in red, as shown.

All parts of the message except the specified bit are ignored. The specified bit index

increases from low bit to high bit in each byte of the message contents, and from early bytes

to late bytes.

The Input CAN Mode option-group appears when Target CAN message is selected. There

are two trigger modes available.

Bit High means that a “high” (1) bit in the specified bit of the message is an incoming

trigger. A “low” (0) bit in the same location revokes a previously-sent trigger, if it has not

already been consumed by starting a cycle.

Bit Low means that a “low” (0) bit in the specified bit of the message is an incoming trigger.

A “high” (1) bit in the same location revokes a previously-sent trigger, if it has not already

been consumed by starting a cycle.

11.6 [Input Triggers]: The Help-text

A short Help message is displayed at the lower left of the form, below the other controls.



11.7 [Input Triggers]: The Obsolete Default CAN trigger

Previously, a Default CAN trigger existed, which could be used to control triggering from the

application. This could only be used from scripting. The Ramp Up and Down waveform

used it to re-configure the U2 voltage parameter from cycle to cycle. This trigger was only

available as an alternative to the other user triggers, and so the Ramp Up and Down

waveform could not be externally triggered. This trigger option is now intended for use as a

Configuration trigger, to ensure that a waveform being played will halt at the beginning of

each new cycle for new configuration options to be sent if desired. It has been made

independent of the other input triggers, and has been removed from this form entirely. This

means that Ramp Up and Down waveforms can now have external triggers.

The Configuration Trigger is an output trigger, and is documented here in the next chapter.



12 The Output Trigger Configuration form

This form appears when the [Output Triggers] tab is clicked in the tab-bar of the Input

Triggers form. It allows output triggers to be configured. Output triggers are independent of

input triggers.

Only those controls relevant to the currently-chosen trigger options are enabled. In a few

cases, where different controls are displayed according to the currently-chosen trigger

options, none will be displayed if it does not apply. This picture shows a fairly full set, with a

user-configured CAN message used as an output trigger.

12.1 [Output Triggers]: Return to the previous form



12.2 [Output Triggers]: Saving the settings


(not just the trigger settings) to the currently-selected profile.





12.3 [Output Triggers]: Viewing the application help document


Help


12.4 [Output Triggers]: The tab-bar

Below the title and the row of hot-spots is a tab-bar.


Clicking on the [Input Triggers] tab in the tab-bar brings up the Input Triggers form.



12.5 [Output Triggers]: Using the Additional Configuration Trigger for

scripted configuration changes

The underlying mechanisms for supporting the Configuration Trigger for Ramp Up and

Down waveforms have been made more robust. It is now much easier for users to use the

COM interface to re-configure (other) waveforms while they are being played. See Changes

to the COM input trigger interface since earlier releases for further details. When the

LVTGO-VBS is waiting for a configuration trigger, it shows Waiting for Config. Trigger in

the Current Step display on the Waveform Main form. On receiving a configuration trigger,

it will proceed to trigger as configured; a combination of a Configuration Trigger and Free

Running will only wait for the configuration trigger at the start of a new cycle. Otherwise it

will wait until a trigger has been sent. It may have already been sent before waiting for the

Configuration Trigger.

Users who wish to use a Configuration Trigger in combination with an Extremely Fast

Transient Burst Noise waveform must note that U1 settings are only updated when a cycle is

(re-)started, but U1 is set at the end of a cycle to be correct at the beginning of the next cycle.

For this reason, the U1 setting current when a cycle is (re-)started from the application (rather

than from a trigger) will be used for the next following U1 and also for the U1 voltage which

begins the next following cycle. It may be necessary to configure a dummy cycle initially

which is used to set the U1 value for the beginning of the first real test cycle following. This

problem is re-created whenever a cycle is stopped from the application and re-started; that is,

the current U1 settings when re-starting are used both for that cycle and for the beginning of

the next following cycle. This does not prevent randomisation from changing the U1 voltage.

It is unusual, but possible, to use randomised settings while explicitly changing the

configurations using the Configuration Trigger. On the other hand, it is unusual to stop and

re-start in the course of an Extremely Fast Transient Burst Noise waveform.

For an EFTBN waveform, there is a special consideration which applies to changing the U1

setting while the cycle is playing. Because each cycle ends by driving the voltage to the U1

value for the next following cycle, the U1 settings set when a cycle is (re-)started will still be

used for the next following cycle. This does not prevent the same settings producing different

U1 values because of randomisation, but it does affect the use of the Configuration Trigger.

12.6 [Output Triggers]: Triggering Ramp Up and Down waveforms

This uses the new Configuration Trigger, where previously it used the old Default CAN

trigger. This change is almost completely transparent to users. The main difference is that it

is now possible to use an additional user input trigger. Existing Ramp Up and Down profiles

included by add2 with the LVTest Application always specified the use of the “Default

CAN” trigger, but in fact forced the use of it whatever the profile specified. The current

version of the application will respect any other setting in the profile, but a “Default CAN”

setting will be replaced with “Free Run” (this may be written back to the profile to change it,

but this is backward-compatible).

The changes in the CAN triggering mechanisms mean that the firmware MUST be updated to

at least version 3.0.0 in order to play Ramp Up and Down waveforms correctly.



12.7 [Output Triggers]: Output triggers

The Output Type option-group specifies whether output triggers are emitted, and if so the

output mechanism used for the trigger.

The point at which the trigger should be emitted is defined by the following set of controls:

Here the trigger occurs 0ms after the point at which the waveform starts time-step T0. This is

rather specialised, as T0 only occurs at the beginning of Cycle 0, and even then only if the

starting cycle is 0 rather than 1: it does not occur at all for Captured or Micro-Cutouts

waveforms. To trigger at the beginning of each cycle, use T1.

Time spent waiting for a trigger is between cycles, not at the end of the previous cycle. The

“waiting for a trigger” state (like the “stopped”, “paused”, “calculating non-played cycles”

and “checking cranking voltages” states) cannot be selected for triggering. A trigger may

only be configured to be emitted at some time within one of the numbered Tn states which

can be configured on the Timing and Frequency Configurations form. Time spent paused is

not counted towards the delay. Remember that Stop followed by Play will re-start at the

beginning of the current cycle.

An offset of 0ms will actually send the trigger just before the output voltage is first driven to

reflect the new step, except for the first time-step of an EFTBN or ramp waveform (or, not

very usefully, a fixed battery voltage). If the defined step is short, the trigger may be deferred

into a later step, but not into the next cycle. However, if the defined step never occurs (e.g.,

T3 in a random cranking waveform) the trigger will not be emitted.

Micro-cutouts waveforms have accurately-timed pulse-streams, but the beginning and end of

the pulse-streams are not very tightly synchronised with the mechanism for generating output

triggers. At present (V5.0.0 of the firmware) there can be up to two milliseconds of “drift”

between the end of step T1 and the beginning of step T3. This affects triggers which are

anchored to step T2, to the end of step T1, or to the beginning of step T3.

Alternatively, the trigger can be timed backwards from the end of the specified time-step.

The controls then look like this:



The length of a playing step is not calculated (even if it is a fixed value) until the beginning

of the step. This means that a trigger will never be emitted before the beginning of the step to

which it is anchored. If a configured offset before the end of a step turns out to be less than

the total length of the step, the trigger will be emitted as soon as this is known (typically

within 1ms of the voltage being driven).

Time spent paused is, again, not counted towards the delay – nor can it be, of course.

Positive and negative offsets cannot both be set at once. However, the application stores the

last-used offset value for each, so switching between “after start” offsets and “before end”

offsets will bring up the previously-used value.

The clock used for emitting output triggers ticks every complete millisecond. If the end of

the step to which it is anchored falls in the middle of these milliseconds, the trigger may be

output up to 0.5ms early or late. The beginning of every Random Cranking or Ramp cycle is

on a millisecond boundary: a run of EFTBN cycles always begins on a millisecond boundary.

A pause is always for a number of milliseconds, and will not make a difference to this.

12.8 [Output Triggers]: Triggering on a scaled time-step

If the time-step from which the offset is measured is scaled, then the delay time is also scaled

accordingly. This allows triggers to be emitted at any point during a long time-step, but it

also means that the delay shown or entered on the control is misleading. Unfortunately, the

scaling on the time-step and the setting of the delay are on separate forms and may happen in

either order, so any way of presenting the delay with scaling may be misleading.

12.9 [Output Triggers]: Output triggers - analogue

Output triggers take the form of an analogue pulse or a user-configured CAN message.

If an analogue trigger is chosen, the following controls are enabled:

The pulse width can range from 1ms to 65.535 s, in 1ms steps. The pulse is a square pulse of

5V amplitude on the selected output. The outputs are to Pin 1 or Pin 2 of the output D-Sub

15 connector of the LVT.



Formerly, Pin 1, when not selected for triggering, was used to report the heat-sink

temperature. Pin 2, when not selected for triggering, was used to report the trip state. This is

no longer true; when not in use, the output voltage should be about 0V on these pins.

However, Pin 1 is used internally for Micro-Cutouts waveforms, and Pin 2 will be used

internally for Nano-Cutouts waveforms (not yet implemented). See the

Output_Triggers_Disconnect_Warning later.

12.10 [Output Triggers]: Output triggers – CAN

If the output trigger is selected to be a user-configured CAN trigger, the following controls

are enabled:

It is possible to send a CAN frame of any permitted length, with a “payload” of from 0 to 8

bytes. However, if the length is 0 bytes the editable Message Contents field will be disabled

(as it appears here). Warning messages are displayed if the CAN ID is too large or if the

message contents have the wrong length. The square brackets used for the Message

Contents may be omitted, but will be used when displaying the message in the control after

editing it.

There is an important difference between the input and output forms of user-configured CAN

triggers. An input trigger carries level information which is interpreted in terms of the trigger

type. An incoming CAN message, depending on its contents and on the trigger type, may

cause a trigger, or no trigger, or cancel a previously-issued trigger. The model for outgoing

triggers is much simpler. The appearance of the configured message is itself the trigger, and

the LVT itself has no way to reverse or revoke the trigger.

At the end of a cycle any current trigger is re-set. This only makes a difference if an

analogue trigger pulse begins very nearly at the end of the last stage of the waveform, and is

cut short at the end of it. This does not depend on whether the cycle ends waiting for a

trigger or not.

12.11 [Output Triggers]: Additional analogue triggers

There is an alternative way to configure analogue output triggers, though it is not supported

in versions of the firmware before 1.4.0. It is in many ways more flexible than the existing

simple pulse-generator, but is incompatible with it: the associated controls for Pin 1 and Pin 2

will not appear if the output trigger is already configured to use an analogue pulse on Pin 1 or

Pin 2. The Pin 3 and Pin 4 output triggers are independent of any other output triggers.



A condensed set of controls is shown in the lower left-hand corner of the form. These

controls are divided into eight sets, configuring arising and a falling edge for each of the

output pins. Pins may not be available for three reasons:

(a) the target hardware configuration may not support them (Pins 3 and 4 are not supported

on most LVTGO-VBS units), or the hardware configuration may not have been read

successfully from the target.

(b) Pin 1 and Pin 2 will be disabled if either of these pins is used as a pulse output trigger.

(c) Warning: Pin 1 triggers (of either form) are disabled if Micro-Cutouts waveforms are

selected; Pin 1 must be disconnected from any trigger circuitry in use. Pin 2 triggers (of

either form) are disabled if Nano-Cutouts waveforms are selected; Pin 2 must be

disconnected from any trigger circuitry in use.

Any triggers that are currently not available for any of these reasons are represented as a row

of visibly disabled controls.

In addition, an available pin can be disabled (e.g., while it is being configured). This is

controlled by the Enable tick-box at the left-hand end of the associated row of controls.

The configurations for output pins 1 to 4 are similar but independent, each on its own labelled

line of controls. They are divided into Rising Edge and Falling Edge settings. The interface

is a condensed version of the analogue-trigger interface. The choice between timing after the

start of a step or before the end of a step is still present, but is represented by a tick-box under

the heading Offset Negative (ticked for “negative” delays, before the end of the step, and left

clear for “positive” delays, after the start of the step). Edges timed from the end of a step will

not actually be driven until the step begins and its length is known (typically within 1ms of

the voltage being driven).

Configuring these triggers causes an initial voltage to be driven to the associated output. To

prevent this from oscillating while the trigger is being configured, or because the associated

output is not to be used for triggering, the triggers for each pin can be disabled. Simply un-

tick the Enable tick-box at the beginning of the relevant line of controls. If the trigger is not

enabled, and the pin is not in use for Micro-Cutouts or Nano-Cutouts, the output on the pin

should be about 0V.



The rising edge (High) and falling edge (Low) may occur in either order. If both edges occur

during the same millisecond time interval no pulse is emitted (the trigger output is not

updated in between the two edges), but the final voltage level will be low, so there may be a

falling edge. The initial trigger level after modifying the configuration, or after Enabling a

configuration already modified, is determined as follows. The trigger level attempts to reflect

the expected state at the end of a waveform cycle. If the waveform steps to which the edges

are anchored are not the same, the edge tied to the earlier step is assumed to occur earlier than

the edge tied to the later step. If the edges are anchored to opposite ends of the same step

(that is, one of them is triggered some time after the start of the step, and the other is

triggered some time before the end of the step) then the initial level is arbitrarily chosen to be

low. If the edges are anchored to the same end of the same step, they are treated as occurring

in the order implied by the specified delays.

This simple heuristic can yield the wrong initial voltage, especially if configuring a trigger

while the waveform is not stopped. However, once one of the configured edges has been

generated the subsequent behaviour should be correct.

If both edges are anchored to the same end of the same step, and with the same delay, then

they will always occur simultaneously (if ever). In this case the trigger level is held

permanently low and will not vary. This may be useful simply to suppress the usual analogue

output for the pin when no trigger is to be emitted.

The timer waiting for an edge to be emitted is reset at the beginning of the step to which the

edge is anchored. This means that if a positive delay has not timed out by the time the step is

re-entered on the next cycle the edge will not be emitted.



12.12 [Output Triggers]: The Help-text

A fairly long Help message is displayed in the right-hand side of the form, below the tab-bar.

12.13 [Output Triggers]: Changes to Controls for Micro-Cutouts

If a Micro-Cutouts waveform is selected, then Pin 1 will be disabled irrespective of any other

settings: the following controls are updated to reflect this:



13 The Miscellaneous Settings form

This form is reached by clicking on the [Misc. Settings] tab in the tab-bar of the Waveform

Main form.

This form provides diagnostic information such as the measured output currents and voltages,

the battery supply voltage, and the heat-sink temperature of the LVTGO-VBS. It also gives

access to the Errors and Special Values form, the Trip Status form, and the HIL Inputs form.

This group of forms is not necessary for routine playing of simulations.

13.1 [Misc]: Return to the previous form



13.2 [Misc]: Navigating to specific forms

Clicking on the [Special Values] hot-spot to the right of the [Back] hot-spot brings up the

Error Status and Special Values form.



Clicking on the [Trip Status] hot-spot to the right of the [Special Values] hot-spot brings up

the Trip Status form.

Clicking on the [HIL Inputs] hot-spot to the right of the [Trip Status] hot-spot brings up the

HIL Inputs form.

13.3 [Misc]: Viewing the application help document


Help


13.4 [Misc]: The tab-bar


other forms.


Clicking on the [Special Values] tab in the tab-bar brings up the Error Status and Special

Values form.

Clicking on the [Trip Status] tab in the tab-bar brings up the Trip Status form.

Clicking on the [HIL Inputs] tab in the tab-bar brings up the HIL Inputs form.



13.5 [Misc]: The Cycle-number streaming control

The [Auto Cycle Type] radio-buttons at the left below the tab-bar control the return of

progress information from the LVT. Information not configured to be returned is not shown

on the Waveform Main form.

If the LVT is stopped (not necessarily if it is paused), this information is always sent

promptly from the LVTGO-VBS unit.

The As Polled setting causes the current cycle number and step to be polled at the frequency

set by the Read Graph Interval control on the Main Menu. This is normally only used for

very fast EFTBN waveforms“rattle tests” where steps, and indeed entire cycles, are so

frequent that the data-stream becomes too fast to handle.

The Every New Cycle setting causes the current cycle number (and step) to be sent from the

LVTGO-VBS unit each time a new cycle begins, or the unit enters a Stopped state (trip states

and pauses are not, in themselves, Stopped states). If the Configuration Trigger is enabled,

this option causes the cycle number and step to be sent at additional times, indicating not

only a change in cycle number but also when the unit is and is not ready to be configured for

the next cycle.

The Every New Step setting sends the current cycle-number and step to be sent each time the

LVTGO-VBS unit enters a new step (or enters or leaves the Paused state). This is normal

and recommended for all waveforms other than very fast EFTBN waveforms, or

(conceivably) captured waveforms only a few milliseconds long.

Settings re-named since earlier versions

The settings on this control have not changed, although their descriptions have. As polled was

previously Never. This was correct (because the data is being polled instead of being

streamed automatically) but misleading (because it suggests that the information was not

being sent). Every New Cycle was previously Every New Frame, which was simply a slip.

Every New Step was previously Every New Phase, reflecting an older term which has been

abandoned elsewhere in the interface.



13.6 [Time]: The GO Feedback control

This control allows the user to choose the way in which the LVTGO-VBS unit responds to

irregular ground-offset voltages detected at the unit.

If you are not using a ground offset, then you should always pick None here. You should

also use the supply ground for the device under test: that is, the VGND (0V) terminal at the front

on a rack-mounted LVTGO-VBS unit, and the GND IN terminal at the back on a free-

standing unit.

If you are controlling the ground offset away from zero, you should use the GND OUT

terminal for the device under test.

The ground-offset output GND OUT is always driven directly from the intended voltage.

Raw adjusts the VB OUT voltage to compensate for the difference between the target ground-

offset and the ground-offset voltage actually read. None ignores the ground-offset voltage

read-back entirely. It is intended for use when there is a great deal of noise in the ground-

offset line, or the target VBatt voltage is modifying the ground-offset, and itself changing too

fast for the feedback to work usefully. Smoothed is useful when the target VBatt voltage is

not changing very rapidly, and the ground-offset circuit is moderately noisy.

In general, Smoothed is the safest option if you are using a non-zero ground offset.

13.7 [Misc]: The logging-compression controls

These are a pair of controls which work together to control the lossiness of compressed

logging for the voltage output and readbacks (parameter values, when logged, are compressed

losslessly, and these controls do not affect this). For full details, please see

VisualConnx.chm.

When the Compress option controlled by the Compressed tick-box on the Waveform Main

form is selected (the tick-box is ticked), lossy compression is used on the data. The first

value encountered is logged. Subsequent values will be logged if they differ from the last

logged value by the specified fraction of the total range for the control, or failing that the

data-stream is down-sampled by the specified factor.

The rate at which these logged values are sent back from the LVTGO-VBS is set using the

Main Readback Interval (ms) control on the Main Menu. Downsampling by a factor n is

performed by selecting every nth value to save to the log.

visualconnx.chm::/html/TransientandordecimationcompressionType2.html



The left-hand control sets the smallest change in data being logged which guarantees that the

new value is retained in the log. It is expressed as a percentage of the total range of values

allowed for the control being logged, by which the value has to change since the last logged

value in order to be logged. Each the loggable values has 256 possible reported values.

For the main voltage values and the input voltage readback the range is 0V to 25.5V in 0.1V

steps.

For the Ground Offset values, the range is 0V to 2.55V in 0.01V steps.

For the Current readback, the range is 0A to 127.5A in 0.5A steps.

For the Temperature readback, it is -40 °C to 215 °C in 1 °C steps.

The right-hand control is used to modify the rate of data-logging when a logged value does

not change outside the window set by the threshold control. With the given setting of 1000,

only one sample point in every thousand is saved to the log.

13.8 [Misc]: The data-retention control

This control sets the maximum amount of data which is retained on the strip-charts which

display streaming data. These are the readbacks strip-chart on this form, and the main output

strip-chart on the Waveform Main form.



13.9 [Misc]: The readbacks strip-chart

Below the tab-bar, this form is largely taken up with a strip-chart showing several values

streamed from the LVTGO-VBS unit. These include the measured temperature at the heat-

sink, the measured ground-offset and load voltages, and the currents measured in both the

ground-offset and load circuits (which should be equal). All these are scaled over the range 0

– 255.

Temperature – measured at the heat-sink / 1 ºC + 40

That is, 0 represents -40 ºC and 255 represents 215 ºC

Input Voltage – the measured input battery voltage / 0.1V.

GO Target – the intended ground-offset voltage / 0.01 V.

Current (H) – the measured current through the load / 0.5A

Current (L) – the measured current through the ground-offset circuit / 0.5A

Voltage (H) – the measured voltage across the load / 0.1V.

Voltage (L) – the measured ground-offset voltage / 0.01V.

Current (H) should be equal to Current (L).

The Strip-chart has a legend, as follows:

This shows the pen colours used to draw each of the readback values on the strip-chart, and

the latest readback value, scaled to appropriate units.



14 The Error Status and Special Values form

This form is reached by clicking on the [Special Values] hot-spot, or on the [Special Values]

tab in the tab-bar, of the Miscellaneous Settings form.

It shows information returned by the LVTGO-VBS unit about its error status, some

identifying information about the unit's hardware and firmware, and gives limited access to

some special settings. In particular, it gives read-only access to a large number of settings.

This form also gives access to the Trip Status form, and the HIL Inputs form. This group of

forms is not necessary for routine playing of simulations.

14.1 [Special]: Return to the previous form



14.2 [Special]: Navigating to specific forms

Clicking on the [Trip Status] hot-spot to the right of the [Back] hot-spot brings up the Trip

Status form.



Clicking on the [HIL Inputs] hot-spot to the right of the [Trip Status] hot-spot brings up the

HIL Inputs form.

14.3 [Special]: Viewing the application help document


Help


14.4 [Special]: The tab-bar


other forms.




Values form.





14.5 [Special]: Error status

The main display on the left below the tab-bar shows Error Status Information. This shows

errors other than hardware errors such as trips. These are either errors in the CAN

communication channel, or in the contents of CAN messages received. There is also a bit

which records when a trip has occurred. When an error status message is sent, the

corresponding bit is cleared in the LVT, so it disappears from the current error message when

it is next sent. This applies even to the trip bit if the trip is still present when the next error

status message is sent.

Normally the error status is updated to the application without user intervention. However,

an update can be forced by pressing the [Update Error Status] button. This may lead to an

entirely blank message (with no errors to report).



So that old error states are not simply lost, the display shows two columns of simulated

LEDs. The left-hand column shows the last reported error status. The right-hand column is

initially all clear, and shows cumulatively all the trips which have been reported. The [Clear

Error History] button can be used to clear all the entries in the cumulative display. The LED

showing red in the cumulative display shows that the a trip has previously occurred, but that

the trip state is not current.

Incompatible firmware

The Bad Firmware Version error is important. It can arise because the firmware is

incompatible with the current version of the GUI, or because it does not seem to match the

hardware of the LVTGO-VBS unit. In this case, unusually, all the LVTGO-VBS outputs are

driven to zero (as if the unit were tripping), but there is no indication on the Status LED of a

trip.

Spurious errors

The Bad Other Setting error reported above is not necessarily evidence of software failure or

of corruption in the CAN communication. Configuration settings are typically updated

piecemeal, and this can give rise to intermediate configuration states which are rejected as

inconsistent (this is especially common when adjusting the pulse width of an analogue output

trigger). Similarly, the Special Value Bad Value error probably arose because a request to

read a value occurred when the value to be read had not yet been configured. Unless these

errors persist, they can be ignored.

14.6 [Special]: Version numbers

The upper right-hand part of the form shows the serial number of the LVTGO-VBS unit, and

the version numbers and build dates of the firmware and the boot-code. There is also some

hardware ID information which is used when re-flashing the unit. Please include this

information in error reports to add2 Ltd.



14.7 [Special]: Make settings persistent

In the middle of the form are the Make Settings Persistent controls. They can be used to

save some values to the Flash ROM on the LVTGO-VBS unit after modifying them.

The [T U and F Parameters] button sets the initial state (at power on) of the waveform

generator. These settings are of limited use. The LVTGO-VBS unit powers on in an

analogue control mode in which the saved waveform is not played, and these settings are

overwritten by the host application after loading a waveform profile.

The [Wave Generator Settings] button saves several additional parameters governing the

behaviour of the waveform generator. Specifically, the saved items are

the waveform type

the number of EFTBN steps

the Max Output Voltage

the Voltage After Test

the Fast Output setting

The first is chosen from the Main Menu; the others are set on the Voltage Configurations

form.

The Serial Number can also be saved (after modifying it with the Special Values interface, as

described later).

The [HIL CAN Base ID] button is used to save the current state of the base ID (as set from

the Special values interface).



14.8 [Special]: The Special Values interface

The middle of the lower part of the form holds the Special Values interface. This gives

access to a large number of values which are otherwise inaccessible. Depending on the

version of the firmware on the LVTGO-VBS, more or less of the interface may be available.

The values are broken down into different categories; only the list for the current category is

displayed. The first item is a pull-down menu for choosing the category (or None). Only

categories supported by the current firmware are shown. However, they may be shown even

if the required hardware is not present – for instance, current versions of the firmware will

cause a list of values associated with the state of Micro-Cutouts wave-forms to be shown,

even if there is not a Micro-Cutouts board fitted.

The second item is a pull-down menu for the values available in the category. Normally all

of these will be supported by the firmware, though they may be of limited use if they

represent features not currently in use.

If the value can be modified by the user (at present, this is only enabled for the HIL CAN

base ID) an editing box appears which allows the value to be changed.



Edit the value in the editable field below, in the usual way. The modified value should

appear in the non-editable field above when the LVT reports it as changed.

HIL CAN messages are used for real-time voltage control and parameter value reporting. It

may be useful to change the base address to avoid clashes with existing message IDs on the

Target CAN bus. However, if the value is changed it will not then be possible to monitor the

parameter values using VISUALCONNX without special re-configuration.

When the value is reported as changed successfully, it can be made the permanent default on

the LVTGO-VBS unit using the [HIL CAN Base ID] button on this form.

14.9 [Special]: The output-range controls

These controls are for cases in which the LVT output must be restricted as input to an

external amplifier, which applies its own gain to the input. The setting is not saved as part of

any profile, but to the main LVTest.ini file for the installation. The LVT will operate

normally, except that it will limit its output voltage to the specified range (or the maximum

output voltage). The voltage readbacks will be reported as though already given the stated

scaling. However, the actual voltage delivered out of the VBatt terminal will be as

configured, subject to this limit.



Normally this tick-box is un-ticked, and the pull-down menu is not visible. This represents

the normal configuration, in which the output range used for the VBATT output of the

LVTGO-VBS is the nominal output range 0V-20V (for a 20V unit), or 0V-30V (for a 30V

unit).

If the box is ticked, then the pull-down menu appears, initially with the following setting:

The displayed range is for the currently-attached hardware: it may therefore show as 0 – 30V

x 1. If any output range is chosen other than full range x 1, then the control shows the output

range in red as a visible warning.

If you try to select a range which is not available for the attached LVTGO-VBS unit, or the

attached unit’s configuration has not been identified, then only the zero range can be selected.

If the LVTGO-VBS unit supports 30V output, the only voltage-ranges supported are the zero

range (0V only) and the full output range.

An important incompatible change

Sufficiently recent versions of the firmware (3.0.0 and later) require this control to be

explicitly set to a non-zero value. The default in recent versions of the application is to set it

to the normal output range (0 – the maximum output voltage, 20V or 30V depending on the

unit), but older versions of the application will leave it as zero.

Attempting to connect an old GUI to an LVTGO-VBS unit with such recent firmware will

drive the outputs to zero and beep (0.5s on, 1.5s off) until the control is re-set. A new GUI

(4.0.0 and later) will require that the firmware be recent if the control is set to anything but

the normal output range.



15 The Trip Status form

This form is reached by clicking on the [Trip Status] hot-spot, or on the [Trip Status] tab in

the tab-bar, of the Miscellaneous Settings form, and the corresponding hot-spots and tabs in

various other forms only reached from that form.

It shows the trip status and thermal status of the LVTGO-VBS unit, and can be used to

retrieve the history of its trip status (including time-stamps). It can also be used to clear the

special slow beep and flash which indicates that a trip has previously occurred on the unit.

This form also gives access to the Errors and Special Values form and the HIL Inputs form.


15.1 [Trips]: Return to the previous form



15.2 [Trips]: Navigating to specific forms





Clicking on the [HIL Inputs] hot-spot to the right of the [Special Values] hot-spot brings up

the HIL Inputs form.

15.3 [Trips]: Viewing the application help document


Help


15.4 [Trips]: The tab-bar


other forms.




Values form.




15.5 [Trips]: Inspecting the trip state

The display at the upper right shows the current trip state and, below it, a cumulative display

maintained by the host application showing which trips have previously been reported. This

is separate from the information held in the trip log on the LVTGO-VBS unit itself, and is not

cleared if the trip-log is erased.

The Trip LED on the Waveform Main form is lit when the LVTGO-VBS unit reports that it

is in a tripped state. This is not strictly the same as the behaviour of the TRIP LED on the

LVTGO-VBS unit itself. The TRIP LED indicates by a flashing sequence the highest-

priority trip currently active, and in the absence of a trip it will also flash slowly if a trip has

previously occurred (and not been cleared from the GUI). Some states which are not strictly

trips are indicated similarly. The corresponding information can be found in the trip displays

on this form, or in the Errors and Special Values form, as noted in the next section.

15.6 [Trips]: Trip-like behaviour

Under some circumstances, the LVTGO-VBS holds its outputs to zero, even though a trip is

not reported. There are two ways in which this can happen.

Firstly, if the LVTGO-VBS has started to be configured from the LVTest application, but the

output voltage range has not been configured, the unit may hold its VB OUT and GND OUT

voltages at zero. In this state, the TRIP LED on the LVTGO-VBS unit flashes and the

sounder buzzes at 0.5Hz, with a 25% duty-cycle. Strictly, this is to protect the output

hardware from accidentally exceeding the intended output voltage limit, and this is not a trip

(which is to protect the LVTGO-VBS unit itself). This will happen if the LVTest Application

version is older than 3.0, or if the relevant configuration message has been lost, perhaps

because the LVTest Application was started before the LVTGO-VBS unit has finished

switching on. Ensure that the application version is at least 3.0 and re-start it.

Secondly, if the firmware is incompatible with the LVTest Application or with the detected

hardware of the LVTGO-VBS unit itself, the LVTGO-VBS unit will silently hold its outputs

at zero. The TRIP LED on the LVTGO-VBS unit shows no activity, except perhaps the very

slow pulse indicating that a trip has previously occurred. The Errors and Special Values form

(reached from the Miscellaneous Settings form) will show a red light in the Bad Firmware

Version line of the Errors display. Try stopping and re-starting the GUI.



15.7 [Trips]: Inspecting the trip log

Minimising the trip log at the left produces

this display. Entries for trips recorded after

the beginning of the log are removed, and

the trip state added into the oldest entry,

which is cumulative from the specified

time.

Erasing the trip log rather than minimising

it produces this display. The log consists

only of the initial cumulative entry. No

trips are shown except those which were

current when the log was erased (in this

case, none). The time-stamp for the

cumulative entry is updated to show the

time at which it was erased.

The large display at the left shows the trip log. This is not updated automatically, but must be

fetched by pressing the [Refresh Trip Log] button. The result should be a list of entries, each

of which begins with a count of seconds since the LVTGO-VBS firmware started to run,

followed by the trips. The last entry (and only the last entry) should have the right-hand LED

lit, to show that it is a cumulative entry (when the trip log becomes full, the cumulative entry

is updated with the entries lost from the log).

All entries may be collapsed into a single cumulative entry by pressing the [Minimise Trip

Log] button.



The entire log (including the cumulative entry) can be cleared by pressing the [Erase Trip

Log] button. This is in red because it permanently removes all the history from the LVTGO-

VBS unit. The cumulative entry is re-started, and its time-stamp is updated to show that

previous entries have been removed. This also clears the cumulative record maintained by

the LVTest Application (in the Cumulative line of the Trip State box below the middle of the

tab-bar).

If a trip has occurred, the LVTGO-VBS unit flashes the Trip LED and sounds the buzzer

briefly every few seconds if no trip is current. This state can be re-set (so that the unit is

silent) by pressing the [Reset Buzzer] button.



15.8 [Trips]: Inspecting the thermal information

A simple display of the thermal status is given at the lower centre of the form. The

temperature in degrees Celsius is given (this is also shown on the strip-chart on the

Miscellaneous Settings form). Older LVTGO-VBS unit hardware did not include fan-speed

monitoring. If the fan-speed is available, it is displayed in RPM.

This particular picture shows the LVT resting quietly.

If the fan speed is available, and is significantly different from the target speed, a large red

pseudo-LED is displayed to indicate the failure. Momentary failures are not important (they

represent the time taken for the fan-speed to adjust to changes in load). Versions of the

firmware before 5.1.0 only reported a fan failure if the fan appeared to be stopped.



16 The HIL Inputs form

This form is reached by clicking on the [HIL Inputs] hot-spot, or on the [HIL Inputs] tab in

the tab-bar, of the Miscellaneous Settings form, and the corresponding hot-spots and tabs in

various other forms only reached from that form.

This form also gives access to the Errors and Special Values form and the Trip Status form.


This form is not normally useful. It provides real-time diagnostic information when using the

HIL analogue inputs to control the LVTGO-VBS unit. See the LVTGO-VBS Specification

Sheet for more details.

16.1 [HIL]: Return to the previous form







16.2 [HIL]: Navigating to specific forms



Clicking on the [Trip Status] hot-spot to the right of the [Special Values] hot-spot brings up

the Trip Status form.

16.3 [HIL]: Viewing the application help document


Help


16.4 [HIL]: The tab-bar


other forms.




Values form.




16.5 [HIL]: Viewing the application help document

Clicking on the [Help] hot-spot at the top left of the form brings up a WindowsTM

Help


16.6 [HIL]: The HIL inputs shown numerically, and as binary data

The upper line displays the most recently reported numerical values (0 – 255) of the HIL

inputs.

The two LEDs show the Fast Output and Trigger inputs, treated as binary data. They are

compared against the critical threshold 2.5V (64 in the units of the upper line). The values

read are sampled at roughly 1ms intervals, and after a transition further transitions are

suppressed for 100ms. This debounced reading is shown on the LEDs.

To the left of the numerical display is a legend:

To the left of the LED display is a legend:

16.7 [HIL]: Setting the HIL readback interval

This control is used to set the frequency with which the HIL inputs are sampled. If the

frequency is set to zero then no HIL information will be available.



16.8 [HIL]: Selecting the HIL input to show on the Waveform Main

form

A set of radio-buttons can be used to select one of the HIL inputs (or none of them) to be

monitored on the Waveform Main form. The voltage reading is updated at the specified

frequency.

If the input selected is HIL2 or HIL3 then the display on the Waveform Main form also

shows the interpretation of the same input as a digital signal, as also shown in the HIL inputs

as interpreted display. HIL2 can be used to control the Fast Output setting, though this is

now little used. HIL3 is still important as an analogue trigger input. See the Trigger

Configuration form for further details.

16.9 [HIL]: The HIL strip-chart

The lower part of the form is taken up with a large strip-chart. This shows the same

information as the numerical display, but over time. For each of the graphs, 0 represents 0V

on the external I/O connector pin and 256 (just off the top of the scale) represents 10V.

The preceding diagram shows the Trigger input driven from a fairly rough square wave. The

other inputs are floating near ground, and too low to appear in the strip-chart.

Below the strip-chart is a legend, showing the colours used for the different HIL inputs.



17 Extremely Fast Transient Burst Noise

Set from the Main Menu by clicking on the [Waveform A] button.

The Extremely Fast Transient Burst Noise waveform (referred to as the EFTBN waveform)

simulates a noisy battery supply feed to vehicle electronics. The typical noise characteristic is

one where the supply intermittently drops to a voltage near ground for short periods of time.

The chances of the supply dropping for a short time are greater than for a long time. This test

is sometimes referred to a “rusty file” test, as this is traditionally how noise of this type has

been generated.

The main user interface form is as follows: from the Main Menu it is reached by clicking on

the Configure and Run Test button.

The information given in this section is specific to an EFTBN waveform. For more detailed

information about the form in general, see the chapter on the Waveform Main form, which

you are advised to read.

17.1 [EFTBN]: Change and view duration and cycle information

An EFTBN cycle consists of playing through all the configured number of steps, except that

the first step (T0) is only played for the very first cycle, if the Start Cycle number is set to 0

(the default). Subsequent cycles will have one step fewer than the number configured. E.g.,

with the number of steps set to 6, Cycle 1 will have steps T0 to T5, and subsequent cycles

from T1 to T5.

Previous versions of this application only supported EFTBN waveforms with three steps (T0

and the repeated T1 and T2). The present version allows the number of steps to be set from

two to eight.



This waveform tends to be run over a very large number of cycles with very short steps

(hence the “Extremely Fast” in the name, although relatively low square-waves can also be

generated). It is normally most convenient to play the waveform for a specified number of

seconds, rather than for a specified number of cycles.

The timing settings can be inspected and modified using the Timing and Frequency


17.2 [EFTBN]: Modify the voltage parameters

Click on the [U Settings] tab in the tab-bar of the Waveform Main form or the Timing and

Frequency Configurations form to bring up the following form:

For more detailed information about this form in general, see the chapter on the Voltage

Configurations form, which you are advised to read.

Only the controls applying to the configured number of steps are visible.

For an EFTBN waveform, there is a special consideration which applies to changing the U1

setting while the cycle is playing. Because each cycle ends by driving the voltage to the U1

value for the next following cycle, the U1 settings set when a cycle is (re-)started will still be

used for the next following cycle. This does not prevent the same settings producing different

U1 values because of randomisation, but it does affect the use of the Configuration Trigger.

17.2.1 [EFTBN]: Setting the number of steps

You can change the number of steps in the EFTBN waveform with the control at the top left

of this form. This control is only visible when an EFTBN waveform has been selected.

Enter the voltages required, as using the waveform diagram as a reference for each voltage.

The range of voltages for each of the U values is from 0V to 30V, in multiples of 1 mV.

If a 20V LVTGO-VBS unit, or one which for some reason cannot have its output range

identified, is attached, then the range of voltages is limited to 0V – 20V.



Values entered are not lost when the step-count changes, so this may be changed at any point.

Of course, if the step-count must be increased, until it is set to the new value some of the

associated controls will not be accessible.

The transitions between successive U values are abrupt steps, not ramps.

17.3 [EFTBN]: Modify the time parameters

Click on the [T Settings] tab in the tab-bar of the Waveform Main form or the Voltage

Configurations form to bring up the following form:

For more detailed information about this form in general, see the chapter on the Timing and

Frequency Configurations form, which you are advised to read.

The number of controls shown for an EFTBN waveform depends on the number of time-steps

set on the Voltage Configurations form. The following message appears on the form to

remind the user.



18 Random Cranking Waveform

Set from the Main Menu by clicking on the [Waveform B] button.

The Random Cranking Waveform simulates the battery supply feed to vehicle electronics

during an engine start cycle.


the [Configure and Run Test] button.

The information given in this section is specific to a Random Cranking waveform. For more

detailed information about the form in general, see the chapter on the Waveform Main form,

which you are advised to read.

18.1 [Crank]: Change and view duration and cycle information

A Random Cranking cycle consists of playing through the steps T1 – T2 and T4 – T9 (T3 is not

used). Cycle 1 also contains a T0 period, which can be suppressed by setting a Start Cycle of

1 instead of 0.

This waveform tends to have relatively long cycles of varying length. It is normally most

convenient to play the waveform for a specified number of cycles, rather than for a specified

number of seconds.



18.2 [Crank]: Modify the voltage parameters



For more detailed information about this form in general, see the chapter on the Voltage


For a Random Cranking waveform, the transitions from Uo or U7 to U3 at the beginning of T1,

and from U4 to U7 at the beginning of T9, are abrupt steps, not ramps. The others are ramps.

The U parameters are numbered in a rather confusing order. Use the diagram shown to see

which U parameter controls the voltage during which T step in the waveform.



18.3 [Crank]: Voltage constraints for Random Cranking

For Random Cranking waveforms, the Voltage Configurations form cannot cease to be

visible on the top (using a navigation hot-spot, or a tab in the tab-bar) without causing some

constraints on the settings to be checked. A message-box may be produced warning about

constraints which may be violated, giving the opportunity to adjust the settings before

continuing. The same check is made before trying to save the settings from the same form.

The constraints are

U2 ≥ U5 / 2

U6 ≥ U5 / 2

U5 is the total amplitude (peak to trough) of the sine-wave component. This ensures that the

envelope of the sinusoid cannot descend below 0V.

Here is a sample message-box.

The cases in which the specified range (minimum to maximum) of the voltages always

violate the constraints, and those in which some extreme values do not violate them, are

distinguished. A report that a constraint is “never” satisfied means that if the LVT attempts

to play the waveform it will always appear to hang with the current step showing as

“Checking Voltages” on the Waveform Main form, as it repeatedly tries new random values

to satisfy the constraints. A constraint which is “sometimes” satisfied can produce arbitrarily

large delays at the beginning of the cycle until the constraint is satisfied.

Setting a resolution greater than 1mV may limit the effective range so that a setting reported

as “sometimes”not satisfying a rule may in fact always satisfy it (or never satisfy it). In

principle an extreme case of a normal distribution might also in practice not be encountered

(or not within a reasonable number of iterations). However, the definite statement “the

waveform will not play” should always be correct, and if no warning is given the waveform

should never need to be recalculated.



18.4 [Crank]: Modify the time and frequency parameters



For more detailed information about this form in general, see the chapter on the Timing and


T3 is not used in a Random Cranking waveform; F0 and F1 are not used for any other

waveform type.

The frequency parameters F0 and F1 specify the initial and final frequency of the sinusoid in

step T6. This is in Hz; the range is in steps of 0.1Hz from 0.1Hz to 250Hz. The frequency

changes with uniform angular acceleration.



19 Ramp Up and Down

Set from the Main Menu by clicking on the [Waveform C] button.

The Ramp Waveform simulates the battery supply feed to vehicle electronics during a slow

discharge and charging cycle. This waveform was introduced with version 3.0.9 of the

Application, and version 1.3.5 of the firmware. It is intended to implement the requirements

of the JLR Test Procedure more accurately than the previous Ramp Up and Down waveform,

which is still available under a new name as the Alternative Ramp waveform..



This waveform differs from the Alternative Ramp waveform in using fixed slopes for the

ramps, and deriving the duration of the ramps from the voltage differences used. It does not

support user control of the slope or duration of the ramps. Following the Test Procedure, it

varies the voltage reached between the ramps through a range of successive values. Starting

with Version 3.0.0 of the firmware (Version 4.0.0 of the application) this uses the

Configuration Trigger mechanism. The principal change is that this can now be combined

with other input triggers. See Triggering Ramp Up and Down waveforms for more details.

If greater flexibility is required, it is recommended that the Alternative Ramp waveform be

used with COM scripting.

The information given in this section is specific to a Ramp Up and Down waveform. For

more detailed information about the form in general, see the chapter on the Waveform Main

form, which you are advised to read.

19.1 [Ramp]: Change and view duration and cycle information

A Ramp Up and Down cycle consists of playing through the steps T1 – T5. Cycle 1 also

contains a T0 period, which can be suppressed by setting a Start Cycle of 1 instead of 0.





number of seconds.

19.2 [Ramp]: Modify the voltage parameters



The information given in this section is specific to a Ramp Up and Down waveform. For

more detailed information about the form in general, see the chapter on the Voltage


There may be an abrupt change of voltage between U0 and U1 in the very first cycle, and

when moving from the U3 voltage at the end of one cycle to the U1 voltage at the beginning of

the next. All other voltage changes should be gradual.

The U2 settings are shown differently from the other voltage settings. The U2 value is not

randomised, but programmed to vary from the Maximum value down to the Minimum value

in steps of the Resolution in successive cycles. The actual voltage used is based on the

current U2 settings and the cycle number. The waveform will stop if the Minimum voltage is

already low.

While a test is running, the U2 Minimum control will show the currently-used value. If the

test is stopped, the minimum value will be restored to the control. Saving the current settings

(even while a test is running) will record the minimum value as configured, not whatever

value of U2 happens to be current.



19.3 [Ramp]: Modify the time parameters



For more detailed information about the form in general, see the chapter on the Timing and


For a Ramp Up and Down waveform, it is usually specify a limiting number of cycles than to

a limiting number of seconds. The end-point reached after setting a time in seconds depends

on the Start Cycle and also on time spent inside cycles which are Stopped and then resumed

with [Play].

The ramp time-steps T2 and T4 have slopes as required by the JLR Test Procedure, that is 30 s

/ V for T2 and 5 s / V for T4. This means that the duration of these steps is determined by the

voltage differences between U1 and (the current value of) U2, and (the current value of) U2

and U3. There is therefore no user control of the time-steps T2 and T4.

The slopes are maintained accurately even if U1 and U3 are randomised: the voltage

difference used is the actual difference between the current values for each cycle.

See also the section on Scaling in the Trigger Configuration form.



20 Constant Voltage

Set from the Main Menu by clicking on the Waveform D button.

This waveform allows you to set a constant voltage to be sustained indefinitely. Pressing on

the Increase or decrease will add/remove 0.1V respectively. The voltage may also be entered

as a number – Remember to press the [ENTER] key to send to value to the unit when

entering the value.


the [Configure and Run Test] button.



20.1 [Constant]: Modify the voltage parameters

Click on the [U Settings] tab in the tab-bar of the Waveform Main form to bring up the

following form:

Although U0 (as for all waveform types other than Captured Waveform) can notionally be

randomised, it will only be generated once.

The other settings have their usual effect.



20.2 [Constant]: Modify the time parameters

Click on the [T Settings] tab in the tab-bar of the Waveform Main form to bring up the

following form:

The only active control is the Output Filter control, and that may itself be disabled, if the

LVTGO-VBS unit attached has only the slow output filter.



21 Alternative Ramp

Set from the Main Menu by clicking on the [Free Ramp] button.

The Alternative Ramp Waveform simulates the battery supply feed to vehicle electronics

during a slow discharge and charging cycle. It differs from the Ramp Up and Down

waveform in allowing control of the duration (and so of the slope) of the ramps. It does not

support programmed variation of any of the voltages (though any can be randomised). It

does not impose any special triggering requirements.



For more detailed information about this form in general, see the chapter on the Waveform

Main form, which you are advised to read.

There are no special peculiarities of the settings for the Alternative Ramp waveform.



21.1 [Alt. Ramp]: Change and view duration and cycle information

An Alternative Ramp cycle consists of playing through the steps T1 – T5.



number of seconds.

21.2 [Alt. Ramp]: Modify the voltage parameters



The information given in this section is specific to an Alternative Ramp waveform. For more

detailed information about the form in general, see the chapter on the Voltage Configurations

form, which you are advised to read.

There may be an abrupt change of voltage between U0 and U1 in the very first cycle, and

when moving from the U3 voltage at the end of one cycle to the U1 voltage at the beginning of

the next. All other voltage changes should be gradual.



21.3 [Alt. Ramp]: Modify the time parameters



The information given in this section is specific to an Alternative Ramp waveform. For more

detailed information about the form in general, see the chapter on the Timing and Frequency


It is usually more useful to limit this wave-form to a given number of cycles than to a specific

length of time. The end-point reached after setting a time in seconds depends on the Start

Cycle and also on time spent inside cycles which are Stopped and then resumed with [Play].



22 Captured Waveforms

Set from the Main Menu by clicking on the [Captured Waveforms] button.

This selection is used to replay previously captured waveforms which have been stored on the

LVTGO-VBS unit. These are typically recorded cranking waveforms, but the only general

restrictions are that the sample interval must be a multiple of 0.5ms from 0.5ms to 32.7675s,

and the voltage must lie between 0V and the maximum output voltage of the unit (20V or

30V). Voltages over 20V will saturate at 20V on a 20V unit, though without an error. The

main user interface form is as follows: from the Main Menu it is reached by clicking on the

[Configure and Run Test] button.



The information given in this section is specific to Captured waveforms.

No more than 64 waveforms may be stored at once. Waveforms are selected to be played by

their index number.

Only voltage data may be played back, at a resolution specified as 4, 8 or 12 bits. These are,

for VBatt data, taken over a configured range of integral volts lying in the range 0V to 30V

(e.g., from 7V to 15V). The output stage of 20V LVTGO-VBS units is only capable of

approximately 22mV resolution. 30V LVTGO-VBS units have an output resolution of

approximately 8.3mV. , and there will be rounding to the nearest available output voltage. It

is normal to have VBatt data or VBatt Data with Ground-offset data together. Ground-offset

data by itself is possible, but at present there is no way to control the VBatt voltage while

ground-offset data only are being replayed; VBatt can only be a fixed voltage.

No more than 64K of wave data can be stored in the LVT, including metadata and header

information. The amount of re-playing time this represents is difficult to summarise, as it

depends on character of the original data and of the sampling options used.



Several controls are only shown on this form for Captured Waveforms.

See Selecting and pre-viewing Captured Waveforms for details of these controls.

22.1 [Captured]: Change and view duration and cycle information

A Captured Waveform cycle consists simply of playing through the captured data from

beginning to end. At present there is no provision for parametrising the data.

22.2 [Captured]: Modify the voltage parameters


following form:

The information given in this section is specific to a Captured Waveform. For more detailed

information about the form in general, see the chapter on the Voltage Configurations form,

which you are advised to read,

There are no voltage parameters which control parts of the waveform. However, there are

global settings for the voltage after test, the maximum voltage, and the ground-offset voltage,

and a control for enabling or disabling fast output.

As usual, clicking on the [Pause] button on the Waveform Main form in the middle of a

waveform will sustain the current output voltage until it is re-started with the [Play] button..

When not actually re-playing the voltage data or paused, the output voltage is the voltage

after test. This means that the behaviour when waiting for a trigger is different for a Captured

Waveform than for other waveform types.



22.3 [Captured]: Modify the time parameters

The only active control on the Timing and Frequency Configurations form for Captured

Waveforms is the Output Filter control. To save space, there is no [T Settings] tab in the tab-

bar for this (Waveform Main) form. If you need the Output Filter control, it can be reached

using the [T Settings] tab on the Voltage Configurations form, which can itself be reached

using the [U Settings] tab on this form. The form looks like this:

See also the Captured Waveform controls in the Waveform Main form for selecting a

waveform to play and seeing a preview of the selected waveform. All captured waveforms

consist of a single nominal T1 step. Output triggers may be anchored to this step as usual.

22.4 [Captured]: Importing, Resampling and Managing Captured

Waveforms

The Waveform Main form only controls the re-playing of captured waveforms. The tab-bar

gives links to the Captured Import form, which allows the user to import CSV-formatted

captured data into a form where the application can handle it, and the Captured Transfer

form, which allows the user to inspect and manage the captured waveforms stored on the

LVTGO-VBS unit. In addition, there is a Captured Resample form, which is used to

resample the imported data into the final form actually stored on the LVTGO-VBS unit.

Access to this form is by using the [Captured Resample] tab on the other two forms. There

is no direct access to this form from the Waveform Main form.



23 Micro-Cutouts Waveforms

Set from the Main Menu by clicking on the [Micro-Cutouts] button.

This selection is used to play accurately-timed short pulse-trains.



The information given in this section is specific to Micro-Cutouts waveforms.



23.1 Micro-Cutouts Preview

The Show Preview control appears on this form when Micro-Cutouts are selected. If it is

selected (ticked) the preview pane appears, as follows:

The Micro-Cutouts waveform preview only shows the pulse-train in the middle of the cycle.

The T1 step before the pulse-train is represented as two time-intervals, and the T3 step after it

is represented as two time-intervals after it. T1 and T3 may actually be shorter than this. The

time-units in use are not shown: the time-intervals are defined by the numerical value of T2

multiplied by the time-unit.

23.2 [Captured]: Change and view duration and cycle information

A Micro-Cutouts Waveform cycle consists of an initial T1 stage playing a high voltage, an

intermediate stage during which a pulse-train oscillates between the high voltage and a lower

voltage, and finally a T3 stage during which the high voltage is sustained.

23.3 [Captured]: Modify the voltage parameters


following form:



The waveform diagram exists in two forms. The form shown above is displayed when the

Pulse High option is selected (ticked). If it is unselected, the following diagram is shown

instead:

The information given in this section is specific to a Micro-Cutouts Waveform. For more

detailed information about the form in general, see the chapter on the Voltage Configurations

form, which you are advised to read,

There are currently just two voltages which define the intended waveform profile. These are

the U1 and U2 voltages, re-labelled as Low U and Pulse. Low U is the lower voltage: Low U

+ Pulse is the upper voltage, which is used as the “voltage after test” voltage whenever a

pulse-train is not being driven. The usual global settings are available for the maximum

voltage and the ground-offset voltage, and a control for enabling or disabling fast output. For

Micro-Cutouts waveforms, the voltage after test control is only for information: it shows the

high voltage, Low U + Pulse. This is, as usual, subject to the maximum voltage limit.

There is an additional control, which determines whether the voltage is normally high with

low-going pulses, or normally low with high-going pulses. Details can be found here. In

either case, the voltage during the T1 and T3 steps (before and after the pulse-train

respectively) is always the higher of the two voltages, just as it is used for the voltage after

test.

As usual, clicking on the [Pause] button on the Waveform Main form in the middle of a

waveform will sustain the current output voltage until it is re-started with the [Play] button..

When not actually re-playing the voltage data or paused, the output voltage is the high

voltage. As previously noted, this is the high voltage based on the current value of the Low

U and Pulse settings.



23.4 [Captured]: Modify the time parameters



In this form, like the Voltage Settings form, the waveform diagram will change according to

the current choice of pulse polarity in the Voltage Settings form.

The information given in this section is specific to a Micro-Cutouts waveform. For more

detailed information about the form in general, see the chapter on the Timing and Frequency


This waveform is rather different from the other waveforms in its use of the time parameters.

There is no initial T0 step at the beginning of Cycle 1. There are only T1, T2 and T3 steps. At

present, no randomisation is supported, and T1 and T3 cannot be scaled. T2 is required to be

scaled by a time-unit, set from a pull-down menu. T2 multiplied by the time-unit sets the

basic time-interval of a pulse-train, in which pulses one time-step wide are separated by gaps

which are multiples of one time-interval wide.

Two special controls appear on this form for Micro-Cutouts waveforms only. See the First

Gap Count and Last Gap Count controls on the Timing and Frequency Configurations form

for more details on specifying the number of pulses and the size of the gaps between the

pulses in the pulse-train.



24 The Captured Import form

This form can be reached by clicking on one of the [Captured Import] tabs. These can be

found in the tab-bar of the Waveform Main form when the currently-selected waveform type

is Captured Waveform, the tab-bar of the Captured Resample form and the tab-bar of the

Captured_Transfer form.

This form is used to import external data into a form which can be directly manipulated by

the LVTest Application. Only after importing can it be re-sampled into a form which can be

directly stored on and replayed from the LVTGO-VBS unit.

After importing waveforms and saving them, the next step is usually to go to the Captured

Resample form to re-sample them.

Preliminary warning:

There is a difference between the "current selection" (all the items highlit in the Imported

Waveforms list-box) and the "currently-selected waveform", which is normally the single

waveform most recently clicked on in the list. Neither is related to the waveform currently

selected for playing in the Waveform Main form.

Where information applicable to a single waveform is displayed, it is for the currently-

selected waveform. This information appears in the Waveform Details display.



24.1 [Import]: Scanning the current waveform directory

Initially, whenever the currently-chosen waveform folder changes, and when actions in

another form threaten to modify the contents of that directory, the form will scan the folder

contents. This has no apparent effect on this form, but it affects checking to prevent

accidentally re-importing data. A warning may be issued at this time if a change in the folder

has revealed an earlier import from the same source file.

Scanning the folder contents may take some time. While it happens, most of the controls on

the form are disabled, and this warning label appears over the upper part of the form.

After scanning, the old selection in the Imported Waveforms list-box will be lost and the

currently-selected waveform is merely the waveform most recently processed, which may be

anywhere in the list.

24.2 [Import]: Return to the previous form


previously visible form. Settings are not lost when the form is hidden

24.3 [Import]: Viewing the application help document


Help




24.4 [Import]: The tab-bar


other forms. The tab-bar for this form exists in two versions, depending on the currently-



Clicking on the [Captured Resample] tab in the tab-bar brings up the Captured Resample

form.


24.5 [Import]: Destination Folder control

The Destination Folder text-box is may be edited to change the waveform folder into which

waveforms are imported. The application checks for cases in which waveforms have already

been imported into this folder (this check is made when the folder changes, and when a

waveform is actually imported).

As well as typing in the folder path directly into the editable part of the control, you may

click on the button labelled with an ellipsis [...] to browse to a folder. You will be given the

opportunity to create a new folder. This cannot be done just by typing into the control, to

prevent accidental mis-typing producing new empty folders.

24.6 [Import]: Action Buttons

The [Import CSV Files...] button brings up a dialogue-box in which the user can navigate to

the CSV-format files to be imported. Multiple files can be selected in a single folder using

the Control and Shift modifiers in the usual way. Ctrl-A has its usual effect and selects every

file displayed for the folder.



The format of the CSV file is restricted. The field separator must be a comma. The tabular

data must be preceded by a single line giving headings for the fields (columns). The field

headings must match “Offset” for Ground Offset data, “Voltage” for the battery output

voltage, and “Time” for the time-stamp data. None of the headings is required, though at

least one of Ground Offset or Battery voltage data must be present. No heading may occur

twice, and all other fields in the line must be blank. Leading and trailing white-space will be

trimmed, and the matching is not case-sensitive. A line which does not meet these

requirements is not taken to be a header line. The tabular data may contain data in additional

fields (not those with entries in the header line); these data will be ignored. However, the

designated fields must contain data starting immediately after the header line. Trailing lines

in which all the designated fields are not numerical will be removed, but there must be no

other missing or non-numerical values.

Optionally, additional lines may occur before the header line. The first non-blank line found

before the header line will be used as a text description of the waveform. It is kept with the

waveform data, and can be used to identify it, even when it is stored on the LVGTO-VBS

unit itself.

The selected files will be imported (unless the user cancels, or an error occurs). Another

effect of this control is to remove any current selection in the Imported Waveforms list-box.

Any items successfully imported will form the new selection after the process has finished.

After importing the data, when a waveform is the currently-selected waveform its description

can be edited in the Description control on this form. The description is applied to the

waveform (including all re-sampled versions of it). The Captured Resample form also

contains a Description control, and it can be edited there too. However, it is probably most

useful to edit the description when it is first imported.

Warnings are issued if a waveform appears to have been imported already. Feel free to ignore

the warning and continue (click on the "No" button). You have the opportunity to inspect the

imported waveforms and remove them if they are in fact duplicates. In any case, the

imported waveform is treated as new (it has its own GUID and may be given its own

different Description). The existing imported waveform will not be affected.

This button is normally enabled except when an operation is already in progress. If it is

drawn in grey, it is temporarily disabled.

The [Remove Selection] button removes the current selection from the Imported Waveforms

list-box and deletes the imported data.

This button is disabled if an operation is already in progress, or if there is no current selection

in the Imported Waveforms list-box. If it is drawn in grey, it is disabled.

The [Save Selection] button removes the current selection from the Imported Waveforms

ListBox and stores it in the currently-selected Destination Folder. It is possible that the

GUID first assigned to the imported waveform will have to be changed at this point. If this

happens, a warning is issued to the Activity Log.


in the Imported Waveforms ListBox. If it is drawn in grey, it is disabled.



24.7 [Import]: Imported Waveforms list-box

This list-box shows the waveforms already imported which have not yet been saved to the

Destination Folder using the Save Selection button or deleted with the Remove Selection

button.

This list-box is normally enabled except when an operation is already in progress. If it is


In this control, multiple selections are possible using the Control and Shift modifiers in the

usual way. However, Ctrl-A cannot be used to select the entire contents of the box. The

easiest way to select everything is probably to go to the beginning of the list with the Home

key, select the first item, go to the end of the list with the End key, and shift-clicking on the

last item to select everything.

The most recent waveform clicked on in this box is usually the currently-selected waveform.

Control-clicking on a waveform will make it the currently-selected waveform even if it has

been removed from the selection. However, saving or removing a selection which includes

the currently-selected waveform will cause there to be no currently-selected waveform. The

effect of importing some new waveforms may be to leave any of the new waveforms

selected, or no selection at all. The most recently added will be selected, if any, but it is not

possible to predict which this will be if several waveforms have been imported.

24.8 [Import]: Activity Log controls

Activity Log text area



This text-area displays information about operations performed in this form. The activity log

cannot be edited, but text in it can be selected and copied into the Clipboard to be pasted

elsewhere.

The [Clear Log] button erases the existing contents of the Activity Log

The Verbose Logging tick-box controls the amount of information given in the Activity Log.

The control is normally off, and only errors (on their first detection) and summary

information are reported in the log.

If the box is ticked, then errors are tracked in much more detail. The additional information

is normally only of use to add2 staff in understanding a failure.



24.9 [Import]: Waveform Details display

Graph

When there is a currently-selected waveform, it is displayed here, together with information

about its voltage range and its time-range. The Description of the waveform appears below

the graph as a title.

When there is no currently-selected waveform, the graph is blank.

The Description text-box shows the descriptive text for the currently-selected waveform. It

is blank if there is no currently-selected waveform. By default, this is based on the header

lines in the file from which the data was imported. If no header is found, the path to the

imported file is used instead.

The contents of this text-box can be edited. This gives you the opportunity to edit the

description field to anything you find more convenient. This is part of the data for each

derived waveform which is sent to the LVTGO-VBS unit. The intention is that it can be used

to identify the original data, even if read from the LVTGO-VBS without any additional

information. An unnecessarily long description wastes space on the LVTGO-VBS unit for

each converted version of the waveform stored.



The GUID text-box shows the identifier assigned to a waveform when it is imported.This is a

GUID ("Globally Unique Identifier"). This cannot be edited, and it remains a unique

identifier of the waveform for the internal use of the LVTGO-VBS suite. This is also stored

with each waveform on the LVTGO-VBS unit, and can be used to resolve ambiguities where

multiple waveforms have the same description. The GUID will only be changed if (which is

exceedingly unlikely) it clashes with a GUID already used in the Destination Folder when

saved.

24.10 [Import]: Progress Bar

The Progress bar shows the application working through multiple waveforms when

importing, saving or removing waveforms.

24.11 [Import]: Help frame

The Help frame contains a very short help message.



25 The Captured Resample form

This form can be reached by clicking on one of the [Captured Resample] tabs. These can be

found in the tab-bar of the Captured Import form and the tab-bar of the Captured Transfer

form.

This form is used to resample data from the raw form imported using the Captured Import

form into a form which can be directly stored on the LVTGO-VBS unit using the controls on

the Captured Transfer form. The next step after resampling is normally to go to that form.

See also the chapter on the General discussion of the resampling process.

Preliminary warning:

There is a difference between the "current raw selection" (all the items highlit in the Raw

Data list-box), the "current sampled selection" (all the items highlit in the Sampled Data list-

box), and the "currently-selected waveform", which is normally the single waveform most

recently clicked on in either list. None of them is related to the waveform currently selected

for playing in the Waveform Main form. The intention is that users can check the features of

a particular waveform without selecting it (or anywhere in the current selection) by control-

clicking on it to bring up its details and then control-clicking again to restore its previous

selection state.

25.1 [Resample]: Scanning


another form threaten to modify the contents of that folder, the form will re-scan the folder

contents. This will re-load the contents of the two list-boxes (Raw Data on the left, and

Sampled Data on the right), which represent different views of the waveforms stored in the

currently-chosen waveform folder.



Scanning the folder may take some time. While it happens, most of the controls on the form

are disabled, and the warning label above appears over the upper part of the form.

After scanning, the old selections in the list-boxes will be lost and the currently-selected

waveform is merely the waveform most recently processed, which may be anywhere in the

list.

25.2 [Resample]: Return to the previous form



25.3 [Resample]: Viewing the application help document


Help


25.4 [Resample]: The tab-bar


other forms.






25.5 [Resample]: Waveform Folder control

This may be used to change the waveform folder currently used. The lists of raw waveforms

and sampled waveforms in the list-boxes reflect the contents of the currently-chosen

waveform folder.


click on the button labelled with an ellipsis “…” to browse to a folder.

25.6 [Resample]: The list-boxes

The Raw Data (left-hand) list-box shows the waveforms found while scanning the current

directory which represent the user's original imported source data. Resampling is (at present)

only possible from source data, though it is possible to have resampled data with no source

data associated.



In this list-box, multiple selections are possible using the Control and Shift modifiers in the


easiest way to select everything is probably to press the [Home] button on your keyboard to

go to the top of the list, selecting the first item, pressing the [End] button on your keyboard to

go to the end of the list, and shift-clicking on the last item to select up to and including it.



The most recent waveform clicked on in this list-box (or in the Sampled Data list-box next

following) is usually the currently-selected waveform. Control-clicking on a waveform will

make it the currently-selected waveform even if it has been removed from the selection.

However, deleting the current selection in either list-box (in this case, using the [<<Delete]

button), if it includes the currently-selected waveform, will cause there to be no currently-

selected waveform.

The Sampled Data (right-hand) list-box shows the waveforms found while scanning the

current directory which have been resampled into a form which can be stored and replayed on

the LVTGO-VBS.



In this list-box, multiple selections are possible using the Control and Shift modifiers in the


easiest way to select everything is probably to press the [Home] button on your keyboard to

go to the top of the list, selecting the first item, pressing the [End] button on your keyboard to

go to the end of the list, and shift-clicking on the last item to select up to and including it.

The most recent waveform clicked on in this list-box (or in the Raw Waveform list-box just

preceding) is usually the currently-selected waveform. Control-clicking on a waveform will

make it the currently-selected waveform even if it has been removed from the selection.

Deleting the current selection in either list-box (in this case, using the [Delete>>] button), if it

includes the currently-selected waveform, will cause there to be no currently-selected

waveform.

25.7 [Resample]: Space Used frame

The Space Used frame contains a single control, a percentage box labelled Selection.



The Selection percentage-box shows the fraction of the total storage available on an LVTGO-

VBS represented by the current selection of sampled waveforms. If the amount is too large

to fit (over 100%) the percentage box shows 100%, but within a red ring.

25.8 [Resample]: Activity Log Controls

The Activity Log records information about operations performed in this form.

The activity log cannot be edited, but text in it can be selected and copied into the Clipboard

to be pasted elsewhere.

The [Clear Log] button erases the existing contents of the Activity Log.


The control is normally off, and only errors (on their first detection) and summary

information are reported in the log. If the box is ticked, then errors are tracked in much more

detail. The additional information is normally only of use to add2 staff in understanding a

failure.

25.9 [Resample]: Action Buttons

The [<<Delete] is button erases the current raw selection, removing the associated files and

any resampled version of the same waveform. If sampled versions exist, the user is asked

whether to leave the waveform unmodified or to delete everything. The cleanest way to

remove a waveform entirely is to remove its sampled versions (using the [Delete>>] button

following) first, then this button. It is possible that a warning will still be issued. This

represents sampled versions of the waveform which are not recognised, perhaps because they

are produced by a later version of the software, perhaps because they have become corrupt.


in the Raw Waveform list-box If it is drawn in grey, it is disabled.



The [Delete>>] button erases the current sampled selection. Since a waveform can always be

re-sampled, this is not seen as critical, and will generate no warnings (unless the deletion fails

for some reason).


in the Raw Waveform list-box. If it is drawn in grey, it is disabled.

The [Resample>>] button applies the current settings in the Sampling controls to the current

raw selection. Duplicates (waveforms already sampled with the same options) will be

discarded. See the General discussion of the resampling process for details of this operation.

This button is enabled when there is a current raw selection in the Raw Waveform list-box ,

and there is not an operation already in progress. If it is drawn in grey, it is temporarily

disabled.

The [Save as File...>>] button saves the current sampled selection to a list file, with

extension TSL. It will only allow the file to be saved in the current waveform folder. The

intention is that these files can later be loaded using the Select By File... button, in the

Captured Transfer form, and used to set a selection to be sent to the LVTGO-VBS unit.

This button is enabled when there is a current sampled selection in the Sampled Waveform

list-box, and there is not an operation already in progress. If it is drawn in grey, it is

temporarily disabled.

25.10 [Resample]: Waveform Data frame

The Waveform Data frame contains two items for the currently-specified waveform (or are

blank if there is none).

The Description text-box shows the descriptive text for the currently-selected waveform in

this form, or blank if none is selected. It may be edited here, or in the Captured Import form.

The description is of the waveform, and is common to the raw data and all of its sampled

versions. See the Description control in the Captured Import form for more information.

The GUID text-box shows a guaranteed persistent identifier for the currently-selected

waveform. It is assigned when a waveform is imported, and cannot be changed subsequently.

See the description of the GUID control in the Captured Import form for more information.



25.11 [Resample]: Graph


about its voltage range and its time-range. A copy of the Description text for the waveform

appears below the graph as a title.

When there is no currently-selected waveform, the graph is blank. The amount of additional

information depends on whether the currently-selected waveform is Raw (in the left-hand

Raw Waveforms list-box) or Sampled (in the right-hand Sampled Waveforms list-box).

The display of resampling settings

For a sampled waveform, the settings shown in the second line of the graph header reflect

those actually used, rather than those requested. For instance, if there was no ground-offset

data present, the number of GO bits will be listed as 0 no matter how many were configured

when the resampling was performed. The number of repeat-count bits may also be smaller

than requested. See Special considerations for repeat-counts for details.

25.12 [Resample]: Help Text

This contains a very short help message.



25.13 [Resample]: Progress Bar

The Progress bar shows the application working through multiple waveforms when deleting

raw waveforms, deleting sampled waveforms, or resampling.

25.14 [Resample]: Quick Help

The Quick Help tick-box controls whether the following help-message appears.

QuickHelp text

This is a short help message, which appears when the preceding Quick Help tick-box is

ticked.



25.15 [Resample]: Resampling Controls

This frame contains a number of controls which configure the process of sampling

waveforms.

The VBatt Bits pull-down menu controls the precision with which the main output voltage is

stored after resampling.. The voltage values are by default expressed as a fraction of the

range 0V to 20V of the LVTGO-VBS unit (for maximum compatibility with old firmware).

However, the range may be changed with the control below:

This menu lets you choose the number of bits used to record the information. 0 bits means

that the information will be omitted. If there is no VBatt data in the imported waveform data,

then this will be treated as 0. It is not normally useful to drive the LVTGO-VBS unit with no

VBatt data, but it is possible to drive a controlled ground-offset without it. If no voltage data

at all is both present in the raw data and selected in the pull-down menus, no sampling will be

attempted.

The Limits controls specify the ends of the range of VBatt voltages used. This means that

waveforms which only use part of the available output range need not waste bits of precision.

For instance, if only the range 8V – 13V is of interest, then restricting the waveform to this

range (voltages outside this range will saturate at its limits) will in effect give an extra 2 bits

of precision. This is also the only way to use the full output range of a 30V unit. However,

only LVTGO-VBS units with firmware of version 4.0.0 or higher will be able to play

waveforms with a range other than 0V to 20V, and if the LVTGO-VBS has an output range

of only 20V then the output will saturate at 20V. In any case, the output is subject to the

maximum voltage and also to any restricted output range setting. The LVTGO-VBS unit’s

output control is not made more sensitive by this setting. 30V units have approximately 3600

distinguished output values for VBatt, and 20V units have approximately 900 (subject to

calibration).

No attempt is made to restrict re-sampling to output ranges which are possible with the

currently-attached unit, as the user may wish to re-sample for several possible output units at

once.

The VGO Bits pull-down menu controls the precision with which the ground-offset voltage is

stored after resampling.. The voltage values are expressed as a fraction of the output ground-

offset range of the LVTGO-VBS unit, 2.5V.



This menu lets you choose the number of bits used to record the information. 0 bits means

that the information will be omitted. If there is no VGO data in the imported waveform data,

then this will be treated as 0. If no voltage data at all is both present in the raw daata and

selected in the pull-down menus, no sampling will be attempted.

The Repeat-count Bits pull-down menu controls the storage associated with each stored

voltage to determine the number of consecutive sample intervals to which it can apply.

If the Voltage Change option-group setting is Steps, only consecutive runs at an exactly equal

voltage are considered. If the sampled data includes both VBatt and VGO data, both must be

equal across the consecutive run (not necessarily equal to each other, of course). If the

setting is Ramps, only consecutive runs with exactly equal slopes are considered. Again, if

the sampled data includes both VBatt and VGO data, both must exhibit equal slopes across

the consecutive run (again, not necessarily equal to each other, of course).

For normally noisy measured data, the sampling process produces smaller output if the

setting on this control (i.e., the Repeat-count Bits pull-down menu) is 0 (one sample-point per

sample interval). However, calculated data, or data subject to severe smoothing, may save

space, and may lead to more accurate interpolation of ramps sustained smoothly for several

sample intervals.

In general, no benefit will be seen for setting the control to a higher number of repeat-count

bits, unless the data have been artificially chosen or heavily smoothed. The choice is

effectively usually between 0 or 16 bits, as the smallest number of bits necessary will be

chosen. However, if some parts of the waveform are very smooth and other parts are noisy, it

is possible that the smallest output will be generated for some intermediate setting. This is

unusual.

The Sample Interval (ms) control sets the sample-rate to be used in the sampled data. It need

not match the sample-rate used for the original data. If there is no time-stamp data in the

imported waveform data, or it is being explicitly ignored because of the setting of the next

following control, then this sample interval will be assumed for the raw data being resampled.

The Sample Interval option-group is controls the way in which waveforms are sampled.

There are two choices, which are very briefly described in the next control.

Use time-step



This ignores any time-stamp data present in the imported waveform, and treats the voltage

data as though it had uniform sample intervals equal to the configured Sample Interval (ms).

This is provided for backward compatibility, and is not normally useful.

Use time data

This uses the time-stamp data imported with the waveform. If there is no time-stamp data, it

acts like Use time-step - that is, the samples are assumed to have uniform sample intervals

equal to the configured Sample Interval (ms). This is the default setting, and should normally

be used.

Sample Interval Source text

or

A very brief explanation of the option currently selected in the previous control.

The Voltage Change option-group controls the way in which waveforms are sampled. There

are two possible settings. A very brief explanation of the current setting appears in the next

control following.

Steps

This setting tries to break down the waveform into consecutive runs of constant voltage. This

is only very rarely more efficient than the alternative, unless the waveform is explicitly

constructed as a succession of steady voltage levels.

Ramps

This setting is the default, and is much more generally useful. It attempts to express the

waveform voltages as a succession of segments, joined end-to-end, with uniform slopes along

each segment.

If the Repeat-count Bits pull-down menu setting is 0, then the Steps option may be very

slightly more space-efficient than the Ramps option. Do be aware, however, that when using

the Ramps option the voltages will be interpolated every 0.5ms, if the sample interval is

larger than this.

Voltage Change mode text

or

A very brief explanation of the current setting in the preceding control.



26 General discussion of the resampling process

The following pages describe the way in which imported waveform data is re-sampled, and

the exact effect of the different settings available.

26.1 [Discussion]: Precision settings for the voltages

All controls mentioned are on the Captured Resampling form, unless otherwise stated.

Ground Offset voltages, if Ground Offset data are available, are expressed as fractions of the

range from 0V to 2.5V. VBatt data, if available, is expressed as a fraction of the specified

range. A range of zero length may be specified (though it isn’t very useful). This will simply

output the specified voltage while the captured waveform plays, subject to the usual limits on

the output voltage. The voltage after test setting is not restricted to this range, as it is not part

of the waveform data.

If a LVTGO-VBS unit has firmware older than V4.0.0, it will only be able to play waveforms

for which the VBatt range is 0V – 20V. This is not necessarily the range of the actual wave

data, but the limit set while re-sampling. Voltages outside the specified range which are

found in the data produce warnings, and an opportunity to abandon the current re-sampling

attempt. If the user elects to continue, voltages saturate at the specified limits.

The maximum voltage stored for the waveform is independent of the currently-selected

Output Voltage Range setting, and of the currently-configured Maximum Voltage setting.

However, the actual voltage output is limited by both, and (of course) by the hardware limits

of the particular LVTGO-VBS unit used.

The VBatt Bits pull-down menu and the VGO Bits pull-down menu specifying the precision

to which the voltages in the imported data are retained during resampling. VBatt is the main

output voltage, while VGO is the ground-offset.

The voltages are rounded to the nearest multiple of the least-significant bit, and checked

against the physical limits of the LVTGO-VBS unit. There is one exception. The maximum

attainable voltage is just below the nominal output limit, and voltages above this limit will be

rounded down. For example, if 8 bits of precision are used for the VBatt output, with the

default range from 0V to 20V, then the actual maximum voltage will be 20V(1 - 2-8

) or about

19.922V.

Selecting 0 Bits in the VBatt Bits pull-down menu omits the VBatt data entirely. Similarly,

selecting 0 bits in the VGO Bits pull-down menu omits the VGO data entirely. If the effect is

to end up with no voltage data at all, then no sampling will be attempted.

It is not normally useful to drive the LVTGO-VBS unit with no VBatt data, but it is possible

to drive a controlled ground-offset without it.

26.2 [Discussion]: Options for the time-stamp data

All controls mentioned are on the Captured Resampling form.



The existing time-stamps imported with the data, if any, may be ignored by setting the

Sample Interval option-group to Use time-step, when the voltage data provided will be

assumed to be at uniform intervals of the Sample Interval (ms). This will also be assumed if

there are no time-stamps in the imported data. Otherwise, any time-stamps supplied with the

data are reduced by the first time-stamp, so the initial sample starts at time 0, and are reduced

to the nearest multiple of the configured Sample Interval (ms).

26.3 [Discussion]: The stages of re-sampling


Fitting to the sample interval

If the original data are not sampled uniformly at intervals of the Sample Interval (ms) then

up-sampling or down-sampling – or even both at different parts of the waveform - will be

performed.

The algorithm for down-sampling tries to preserve the original characteristics of the data (it

does not simply discard “excess” data-items). In particular, where data-points have to be lost,

the algorithm tries to identify a replacement for the original data which preserves the initial

and final voltages and preserves any intermediate maximum voltage which is greater than

either and any intermediate minimum voltage which is lower than either. If both an

intermediate maximum and an intermediate minimum occur, they are kept in their original

time-order.

Identifying runs in the voltage data

The resulting envelope(s) of the waveform are consolidated into consecutive runs. There

may be two envelopes because both VBatt and VGO data may be present. Consolidation is

unlikely with real noisy data, as no approximations are allowed. If the Voltage Change

option-group setting is Steps, only consecutive runs at an exactly equal voltage are

consolidated. If the setting is Ramps, only consecutive runs with exactly equal slopes are

consolidated. If both VGO and VBatt data are present, then consolidation is only possible

when both envelopes provide consecutive runs which can be combined.

Please note that a "step" and a "ramp" are not equivalent, even if they are carried out over a

single sample-interval, if the sample-interval is more than the minimum (0.5ms). A "step"

will in this case sustain its initial voltage for the whole of the sample interval, while a "ramp"

will stay at the initial voltage for just 0.5ms, then change progressively every 0.5ms towards

the final voltage. That is, even though the stored sample interval may be much larger, the

voltage output by the LVTGO-VBS unit is controlled every 0.5ms, although this not obvious

if the voltage remains constant.

Re-splitting to fit the repeat count

Finally, the time-intervals between points in the resulting envelope(s) are re-split into the

longest runs allowed by the current repeat-count setting. The repeat-count only specifies a

length of time during which a constant voltage is sustained if the Voltage Change option-

group setting is Steps. If the setting is Ramps, which is the default and more usual, the name

is a slight misnomer. It specifies an interval, as a multiple of the configured Sample Interval

(ms), over which the LVTGO-VBS firmware will interpolate linearly between the end-points.

Of course, it is still possible for the voltage to be equal at the end-points.



If the Repeat-count Bits pull-down menu is set to 0, no repeat-count information is saved, and

samples must be stored for each consecutive multiple of the configured Sample Interval (ms).

If the number of bits is larger, the largest repeat-count available is 2^(number of bits) – 1.

If the voltage envelope(s) of the waveform contain runs longer than this maximum repeat-

count, the run will be subdivided.

If the Voltage Change option-group setting is Steps , this is simply a matter of chopping the

run of constant voltages into the maximum lengths possible, with possibly a shorter run at the

end. If the setting is Ramps, the intermediate points chosen for sub-dividing the run are

chosen to give the most accurate possible slopes for the VBatt data (if present), or the VGO

data (otherwise), subject to the maximum repeat-count.

If, after splitting up the runs to avoid exceeding the maximum repeat-count, the resulting

maximum repeat-count can be accommodated with a smaller number of repeat-count bits,

then the smaller number is used.

26.4 [Discussion]: Special considerations for repeat-counts


Usually, if the waveform allows the use of repeat-counts usefully at all, it is best to pick a

very high maximum repeat-count (i.e., a relatively large value in the Repeat-count Bits pull-

down menu) and see what happens. However, it may happen that there is a long run of

uniform voltages somewhere in the waveform which will keep the maximum repeat-count

high. In that case, it may be worth trying a smaller number of repeat-count bits to see

whether it is more space-efficient (it will not be more accurate in interpolating intermediate

voltages, and will generally be less so). This depends on the precision to which the voltages

are being sampled.

For real captured data, it is almost always worth re-sampling with the Repeat-count Bits pull-

down menu set to 0. There will almost always be a run of at least 2 sample intervals, which

will prevent the repeat-count falling to uniform steps of length 1, but using no repeat-counts

is almost certainly the best way to make the resulting waveform use as little space as

possible.



27 The Captured Transfer form

This form can be reached by clicking on one of the [Captured Transfer] tabs. These can be

found in the tab-bar of the Waveform Main form when the currently-selected waveform type

is Captured Waveform, the tab-bar of the Captured Import form and the tab-bar of the

Captured Resample form.

This form is used to manage captured waveforms stored on an LVTGO-VBS unit. Its main

purpose is to store re-sampled waveforms on the unit, to load waveforms from the unit on to

the host machine (so that they can be previewed, or recovered after accidental deletion), and

to delete waveforms on the unit. Waveforms on the unit cannot be “moved” from one index

number to another; they can only be deleted and re-stored.

As a convenience, it is also possible to delete re-sampled waveforms stored on the host

machine.

Preliminary warning 1:

If the LVTGO-VBS unit has old firmware, it may not be possible to perform the operations

on this form which require communicating with it. These are preceded by warnings if the

firmware version is unknown or too old. Before proceeding past a warning, please save any

work in progress on other forms (e.g., save a profile if you wish to keep any changed

settings), as the application may stop responding until it is stopped. Stopping the application

should still allow a clean exit within a few seconds.

Preliminary warning 2:



There is a difference between the "current host selection" (all the items highlit in the Host

Data list-box), the "current target selection" (all the items highlit in the Target Data list-box),

and the "currently-selected waveform", which is normally the single waveform most recently

clicked on in either list.

27.1 [Transfer]: Scanning


another form threaten to modify the contents of that folder, the form will re-scan the folder

contents. This will re-load the contents of the left-hand list-box (the Host Data list-box). It

has no effect on the right-hand list-box (the Target Data list-box) which shows the waveforms

stored on the LVT.

Changing the currently-chosen waveform folder will not alter the target list, since the

contents of the target have not changed. However, it may no longer be possible to display a

graph of a waveform on the target, if the waveform has not already been imported into the

new folder.

The [Connect and Sync] button will force any sampled waveforms on the target but not in the

current folder to be imported. These have no associated raw data, and will only appear in the

Host Data list-box in this form, and in the Sampled Data list-box in the Captured Resample

form..

Scanning the folder may take some time. While it happens, most of the controls on the form

are disabled, and this warning label appears over the upper part of the form.

After scanning, the old selections in the Host Data list-box will be lost, and the currently-

selected waveform is merely the waveform most recently processed, which may be anywhere

in the list.

27.2 [Transfer]: Return to the previous form





27.3 [Transfer]: Viewing the application help document


Help


27.4 [Transfer]: The tab-bar


other forms.



Clicking on the [Captured Resample] tab in the tab-bar brings up the Captured Resample

form.

27.5 [Transfer]: Waveform Folder control

This may be used to change the waveform folder currently used. The list of sampled

waveforms in the left-hand Host Data list-box reflects the contents of the currently-chosen

waveform folder.


click on the button labelled with an ellipsis "…" to browse to a folder.

27.6 [Transfer]: The list-boxes

There are two list-boxes on this form, occupying the middle of the left-hand side, separated

by a column of buttons. They are not labelled.



The left-hand list-box is the Host Data list-box

It shows the resampled waveforms detected while scanning the current directory which can

be stored on the LVTGO-VBS.

The right-hand list-box is the Target Data list-box

It shows the resampled waveforms successfully read from the LVTGO-VBS after clicking on

the [Connect and Sync] button, or subsequently with the [Load] button.

27.7 [Transfer]: Activity Log Controls

Activity Log text-box



Normally, this records information about operations performed in this form.

The activity log cannot be edited, but text in it can be selected and copied into the Clipboard

to be pasted elsewhere.

The [Clear Log] button erases the existing contents of the Activity Log.

Verbose Logging


This control is normally off (unticked), and only errors (on their first detection) and summary

information are reported in the log. If the box is ticked, then errors are tracked in much more

detail. The additional information is normally only of use to add2 staff in understanding a

failure.

27.8 [Transfer]: Action Buttons

The [Connect and Sync] button reads all the waveforms currently held on an attached

LVTGO-VBS unit and, if not present in the currently-selected waveform folder, it imports

them and saves them. As only the sampled data is available, it is not possible to re-sample

from it, but it can be displayed like any other sampled waveform. Some information about

the source of the data is lost (e.g., the original imported file-name). However, the GUID and

Description are stored with the waveform, and can be used to identify the original imported

data, if it is present in another folder.

If the waveform contents are not recognised (possibly because they were created with a more

recent version of the application), then the resulting waveform entry will be blank.

The waveform entry is not empty, but it may be re-used if a waveform is added to the unit. It

may also cause the amount of storage currently used on the LVTGO-VBS to be larger than

expected given the visible waveforms.





The [>> Store >>] button stores the current host selection to the current target selection on

the LVTGO-VBS unit. If the target selection includes waveforms currently stored on the

target, the operation will not proceed.

If the current target selection contains fewer indexed waveforms on the target than sampled

waveforms in the host selection, unused waveform indices with higher numbers on the target

will be selected for you. If the target selection is empty, the search for unused waveform

indices starts with index 1. If there are not enough unused waveform indices, or the host

selection is too large to fit on the free space on the target, then no waveforms will be stored

on the LVTGO-VBS unit.

At present, waveforms maybe over-written on the target unit because they were not

successfully imported from the LVTGO-VBS unit to the host, perhaps because of a

communication failure, and perhaps because they are in a later format than the LVT

Application can handle. This will be made safer in a future release.

This button is only enabled when there is a current host selection in the left-hand Host Data

list-box, the [Connect and Sync] button has been clicked,, and no other operation is already in

progress. If it is drawn in grey, it is temporarily disabled.

Firmware older than V4.0.0 will store waveforms with output voltage ranges other than 0V –

20V, but will not be able to play them. Firmware at least as recent as V4.0.0 will also accept

waveforms with maximum output voltages above 20V, even if in fact they will have to

saturate the output at 20V.

The [Delete All >>] button can be used to clear all waveforms stored on an attached LVTGO-

VBS unit (if its firmware is sufficiently recent) without having to load any of them to the

application first. In particular, it will delete all waveforms whether or not they are corrupt or

use an unrecognised format. This operation is especially useful before using the [Select by

File...] button to specify a set of waveforms to be sent to the attached LVTGO-VBS unit.

Most operations involving the target will still require you to click on the [Connect and Sync]

button, partly to confirm that the waveforms have indeed been deleted from the target, and

partly to confirm that communication is proceeding normally. However, this synchronisation

operation is quick if there are no waveforms on the attached unit.



The [<< Delete] button deletes the current host selection of sampled waveforms from the

waveform files containing them.

This button is normally enabled if there is a host selection in the left-hand Host Data list-box,

unless an operation is already in progress.

The [Delete >>] button deletes the current target selection of sampled waveforms from the

LVTGO-VBS unit. Waveforms not read successfully from the LVTGO-VBS may be deleted

using this button. This does mean that deleting an apparently missing waveform may silently

delete information from the LVTGO-VBS.



This cannot be used (the Target Data list-box will be empty) if the [Connect and Sync] button

button has not previously been clicked. In this, it is unlike the [Delete All Target] button

previously mentioned.

This button is normally enabled if there is a current target selection in the right-hand Target

Data list-box, unless an operation is already in progress.

This button is only enabled if there has been a [Connect and Sync] operation performed for

the currently-selected waveform folder, there is a target selection in the right-hand Target

Data list-box, and no other operation is already in progress.

The [<<Load<<] button fetches the current target selection in the right-hand Target Data list-

box. It is in effect a selective version of [Connect and Sync]. It does require the [Connect

and Sync] button to have been clicked first. That should fetch all the waveforms from the

target, but if the operation reports errors it makes it possible to re-try with waveforms that

failed.

Waveforms which are corrupt, not recognised, or not successfully read from the LVTGO-

VBS unit are not shown in the list, but will still occupy storage on the unit.

Waveforms can be read from units even if they are unable to play them (e.g., waveforms with

VBatt ranges other than 0V – 20V, on units with firmware older than V4.0.0). Similarly,

even if a 20V unit is unable to drive the requested voltages above 20V, the waveform data on

the unit is still intact and can be fetched. However, versions of the GUI older than V5.0.0

will treat all waveforms with ranges other than 0V – 20V as corrupt, and not display them.

The [Select by File...] button loads a list file, with extension TSL, and uses it to specify the

current host selection in the left-hand Host Data list-box. Any items in the list which cannot

be matched in the current waveform folder will generate a warning. This normally means that

they have been deleted since the list was saved. The file can only be loaded from the current

waveform folder.

The normal sequence for cleanly installing completely new waveforms on the target is

[Delete All Target] button

[Connect and Sync] button

[Select by File...] button

[>> Store >>] button

See the description of the [Save as File...] button on the Captured Resample form.

This button is normally enabled if no other operation is already in progress.



27.9 [Transfer]: Busy Label

(normal state) or

(busy state).

When the application is communicating with the LVTGO-VBS unit, this label shows pale

red.

27.10 [Transfer]: Space Used frame

This frame contains three controls.

The Host Selection percentage-box shows the fraction of the total storage available on the

LVTGO-VBS unit taken up by the current host selection in the Host Data list-box. If the

selection is too large, then the percentage-box shows 100%, but within a red ring. No

account is taken of storage already used on the LVTGO-VBS.

The Target Selection percentage-box shows the fraction of the total storage available on the

LVTGO-VBS unit taken up by the current target selection in the Target Data list-box.

Waveforms may be present on the LVTGO-VBS unit which are not listed, because they are

corrupt, in an unrecognised format, or not successfully read from the LVTGO-VBS.

The Target Total percentage-box shows the fraction of the total storage available on the

LVTGO-VBS unit taken up by the waveforms currently present on it. This may be larger

than the total of the visible waveforms, because of waveforms stored on the unit which are

corrupt, In an unrecognised format, or which were not successfully read from the LVTGO-

VBS.

27.11 [Transfer]: Waveform Details

Details of the waveform appear on various of its controls.

Graph

The upper right-hand part of the form below the tab-bar is used to show a graph of the

currently-selected waveform, together with some basic parameters. Above the graph itself is

a list of the settings used to resample it. These are the settings actually used, rather than those

requested. See The display of resampling settings for more details.




about its voltage range and its time-range, and the currently-used resampling options. A copy

of the Description text for the waveform appears below the graph as a title.

The Waveform Data frame contains two controls, showing information for the currently-

selected waveform.

The GUID display shows a guaranteed persistent identifier for the currently-selected

waveform. It is assigned when a waveform is imported, and cannot be changed subsequently.

See the GUID display on the Captured Import form for more information.

Description

The Description display shows the descriptive text associated with the currently-selected

waveform in this form, or is empty if no waveform is selected. It cannot be edited here (it

may be on the target, where it cannot be modified). However, a local copy may be edited

using the Description text-box on the Captured Resample form. The description is of the

waveform, and is common to the raw data and to all the sampled versions of the waveform.

See the account of the Description text-box on the Captured Import form for more details.



27.12 [Transfer]: Help frame

The Help frame contains a very short help message.

27.13 [Transfer]: Progress Bar

The Progress bar shows the application working through multiple waveforms when

Storing sampled waveforms on the target

Connecting and Syncing

Deleting selected sampled waveforms from the host

Deleting all waveforms from the target

Deleting selected waveforms from the target

Loading waveforms from the target



28 Replaying problematic waveform cycles

It is common for the unit to be used to repeat a specified waveform with randomised

parameters over a large number of cycles. If one of the test cycles appears to cause problems

in a device under test, it is convenient to be able to reproduce the cycle without having to

play through the sequence from the beginning. There are three options.

Firstly, if the problem is detected before the waveform cycle is complete, it can be re-started

from the beginning of the current cycle by using the [Stop] and [Play] buttons on the

Waveform Main form.

Secondly, the problematic cycle number can be noted on the Current Cycle display on the

Waveform Main form. The instructions here show how to set up the waveform to re-start

from the required cycle. The [Reset] and [Play] buttons on the Waveform Main form can

then be used to resume. It is often best to resume before the cycle during which problems

were observed, in case the previous test cycle contributed to the problem.

Thirdly, the parameter value actually calculated and used by the LVT for each cycle are

streamed to the application, which can log them (or the user can log the CAN traffic directly).

Testing can then resume with values in narrow bands around the values actually used when

the problem was noted.



29 Test standards

Many standard tests can be met using either captured waveforms or suitably parametrised

generated waveforms. It is add2 policy to extend its coverage of these, in the form of

captured waveforms and profiles supplied with the LVT Application. The profiles are

distributed through the relevant parts of the profile tree, mostly in their own subdirectories.

Please let us know of any other standards you would like us to meet.

Although the Captured Waveform mechanism can be used for nearly any single waveform, it

does not support randomisation. Additionally, it is hard to specify a degree of quantisation

accuracy in voltage or in time which is good enough for all purposes without making the

resulting data very bulky – perhaps actually too large to be stored on the LVTGO-VBS unit at

all.

The tests specified for CI260 and Section 9.2.16 of the GM test specification GMW 3172 are

met with captured waveforms. They have their own sub-directories in the <Project

Directory>\Sample Sources and <Project directory>\Sample Waveforms directories. Care

has been taken to keep the resulting sampled waveforms as small as possible, while

minimising quantisation errors.

The randomised “rusty file” tests (“Waveform A”) required for CI 265 exist in two copies, as

the test specification was revised at the beginning of 2011, although this family of tests was

not affected. Each copy is in its own dated sub-directory within <Project

directory>\Profiles\Extremely Fast Transient Burst Noise\ . The only difference between the

different profiles in each set is the maximum allowed time between voltage transitions.

The older-dated directory contains another family of profiles, provided for backward

compatibility with previous releases. The only difference is that the high and low voltages

were accidentally transposed. They are in

<Project directory>\Profiles\Extremely Fast Transient Burst Noise\CI265-

2009.05.18\OldErroneousWaveformA\

Most of the profiles provided for Micro-Cutouts are in the CI260 sub-directory.

The profile for the Ramp Test (“Waveform C”) for CI265 is found in two dated sub-

directories for historic reasons, but this test was not affected.

Several different test specifications specify versions of Random Cranking waveforms. In

particular, the very coarsely sampled Random Cranking waveforms of section 9.2.17 of GM

standard GMW3172 are actually realised as synthetic Captured Waveforms.

Additional standards supported:

“Waveform B” of CI265 was originally specified with some parameters missing and some

misprints, so the changes between the two dated versions are important. In addition, the later

specification from the beginning of 2011 is matched with a profile specifically for generating

waveforms B, C and D simultaneously, using relays driven from specially-configured trigger

outputs to derive the B and C outputs from (the usual) output D.

Broadly similar in conception to the CI265 BCD outputs, but very different in detail, the

cranking profile outputs for Ford’s CI 230 test drive outputs A, B, C and D simultaneously on

suitably capable LVT hardware.

Section 9.2.3 of the GM specification GMW3172 is a sharply simplified Random Cranking

waveform, but it can still be met by flattening the sinusoid to zero amplitude.



Section 2.4 of the ISO standard ISO-7637 (with variants for 12V and 24V battery supplies) is

also supported.

CI 265 is fully supported: coverage of CI 260 is not complete, and at present is divided

between Micro-Cutouts and Captured Waveforms.

29.1 CI 230 – some special observations

The test specification leaves several aspects of the waveform undefined. The CI230_ABCD

profile follows the Ford specification, with the following additional features.

The T0 step before the start of the first cycle, and the T9 step in between cycles, are used to

hold the D waveform output at U3 (12.5V) for three seconds. In addition, the A output

produces its first pulse starting 500ms after the start of time-step T1. The second pulse on the

A output ends at the end of the T8 step, when the voltage on the D output falls from U4 to U3,

and the B output is switched off. The length of the T8 step allows the A, B and D output

voltages to remain high together for 500ms after the start of the second A pulse.

Users are free to modify the Voltage and Time parameters, but it is recommended that U0

(during T0) and U7 (during T9) should continue to be equal to U3. The lead-in time with the D

output held at U3, but the other inputs off, can be modified by changing T0 and T9, down to

the minimum lead-in of 500ms built into T1. The lead-out time with outputs A, B and D all

held at U4 can be adjusted by changing the length of T8, after which output D continues at U3

but the other outputs are zero.

The time-offsets specified for the test, starting with the initial A pulse and ending with the

start of the final A pulse, cannot at present be modified, irrespective of the length of T1 and

T8. If A is still high at the beginning of T2 it is switched off immediately, and similarly B and

C will be switched on immediately if this has not already happened. A, B and C will all be

switched off at the beginning of T9. T8 must be at least long enough to start (and detect!) the

final pulse on output A, which begins 325ms into the T8 time-step.



30 Scripting using the COM interface

VISUALCONNX supports external control through a scripting interface over COM. This

makes it possible to run pre-programmed sequences of tests automatically (Test Automation).

The LVTest Application exposes a great deal of its control interface through specially-written

interface functions which can be called in this way. This interface is working towards

completeness in terms of control settings and in supporting polling for data sent from the

LVTGO-VBS unit. There is no mechanism for streaming data over the COM interface.

The application installation includes an LVTCom directory. There is a substantially

complete example in Visual Basic in the form of the VB Test Harness. There is a

WindowsTM

Help file installed in Forms\Help\LVTCom.chm, This gives an overview of a

typical scripting sequence, and detailed interface specifications for the COM interface

functions.

There is also a Python interface class, with a very simple example script. Calls which use

their arguments to return values from the COM interface are called differently from Python

and Visual Basic. The extra arguments are still supplied to the low-level interface, but the

interface class supplies them, so the user need not. However, all the values returned are

returned as a single list to the caller. The example script gives details for the few calls

affected.

The public COM interface for the LVTest Application is described in the Windows™ help

file LVTCOM.chm. A link to it is installed in the Start Menu alongside the link to the

LVTest Application itself (usually in the group Programs|add2).

30.1 [Scripting]: COM scripting and input triggers

The functions and procedures of the COM interface are documented in the Windows Help

file LVTCOM.chm.

Input Triggers other than the Configuration Trigger can be configured over COM just as

when using the controls on the Trigger Configuration form. For backward-compatibility

reasons, the numerical arguments to the COM configuration functions are not obvious from

the corresponding controls on the GUI.

Whenever the COM interface is used to load a profile (this includes the automatic loading of

the last-used profile for a given waveform type when that waveform type is selected), the

input trigger settings in the profile are then modified by the current trigger configuration set

up by the COM interface. This can be used, of course, to over-ride the input trigger settings

in the profile. However, it is possible to configure the COM settings so that the input trigger

type, the input trigger mode, or both, are left unchanged from the settings in the profile.

Now that a Configuration Trigger can be configured independently of the other input triggers,

there is normally no reason to over-ride the settings in the profile. To leave the profile

settings unmodified, call

SetInputTriggerType(1, 0, nRetCode)

early (before loading the profile you want to use). It only has to be called once.

LVTCOM.chm



30.1.1 [Scripting]: Using an Analogue Input Trigger from COM

The trigger modes for analogue input triggers are numbered from 0 to 3 corresponding to the

items in the Input Analogue Trigger Mode option-group in order. There is no change here.

In existing COM scripts, all that is necessary is to replace

SetInputTriggerSource(3)

SetInputTriggerMode(n2)

With

SetInputTriggerType(3, n2, nRetCode)

There has been no change in the modes available for an analogue input trigger.

30.1.2 [Scripting]: Using a User-Configured CAN Trigger from COM

The configuration of input CAN triggers is now entirely different from the old mechanism,

which emulated an analogue trigger, rather wastefully and confusingly. The main reason for

replacing the old calls SetInputTriggerSource() and SetInputTriggerMode() with the single

call SetInputTriggerType() was to ensure that old CAN triggers were not re-used accidentally

with very different effects.

The correspondence between the mode numbers and the positions of the corresponding

entries in the Input CAN Trigger Mode option-group is not obvious.


specified a Bit High trigger.


specifies a Bit Low trigger.

Other values for the second argument are errors: no configuration will be attempted, and

nRetCode will be set to a non-zero value on exit.

There is no exact equivalent to the old User-Configured CAN edge-trigger modes. They all

required two CAN messages to be sent with a gap of at least a millisecond between them.

Now, a trigger is a single message, with the configured bit set high or low as required, and

revoking a previously sent trigger (if it is ever required at all) is a similar message with the bit

state inverted. There is no equivalent at all to the old level-sensitive triggers, which could be

used in effect to switch between free running and stopping the waveform entirely at the end

of the current cycle. However, an almost exact equivalent is to switch between free running

and the use of an input trigger which is not actually available.

Ramp Up and Down waveforms use the Configuration Trigger internally, and this cannot be

disabled using the COM interface. Attempting to re-configure a Ramp Up and Down

waveform from the COM interface while it is running is not supported. In any case, it is

easier to re-configure a ramp waveform cycle-by-cycle using the Alternative Ramp

waveform.



30.1.3 [Scripting]: Using a Configuration Trigger from COM

EnableConfigTrigger(True) will cause the LVTGO-VBS to wait at the start of a cycle for a

Configuration Trigger, if it has not already received one. A Configuration Trigger can be

sent (if enabled) with SendConfigTrigger(True), and an as-yet unconsumed trigger already

sent can be revoked with SendConfigTrigger(False).

30.1.4 [Scripting]: Changes to the COM input trigger interface

A new interface for configuring input triggers was introduced with V4.0.0 of the LVTest

Application. The most pervasive change is that the old configuration calls

SetInputTriggerSource()

and

SetInputTriggerMode()

have been replaced with a single call

SetInputTriggerType()

The old effect of calling


or never calling

SetInputTriggerSource()

at all, has been deprecated for some time, and 0 is not now allowed as the first argument to SetInputTriggerType ()

the call will not change the configuration, and will return with an error code.

Similarly,


to use the old Default CAN trigger is now an error. To use the new Configuration CAN

trigger, the

EnableConfigTrigger()

call must be used instead.

The Mode options for User-Configured CAN Input Triggers have changed entirely.

The previously recommended way to use the input trigger settings as specified in the profile

was to call


SetInputTriggerMode(0),

This is now done with the combined call


If a profile loaded over COM did configure the use of an input trigger (other than Default

CAN), and the COM interface was used to over-ride it with the use of a Default CAN trigger,



then the closest approach possible to the old behaviour using the COM interface is to enable

the Configuration Trigger with

EnableConfigTrigger(True)

and to over-ride the existing profile trigger by calling


to force free running. In fact, if the profile specified a trigger, it is probably most useful not

to over-ride it, and to enable the use of the Configuration Trigger separately if wanted.

30.1.5 [Scripting]: Converting old COM scripts using Default CAN triggers

It is possible that some customers have been using COM scripting to force the use of the old

Default CAN trigger in place of whatever input trigger was specified in the profile. The

closest approximation to this that is now possible is to call

EnableConfigTrigger(True)

to use the Configuration Trigger,


to force free-running. This may happen at any time before playing a waveform, since it

completely replaces the existing trigger configuration, and will continue to do so whenever a

profile is loaded subsequently.

Actually sending a Default CAN trigger was probably only ever done using the old call

SendTrigger().

This can be replaced with the new call

SendConfigTrigger(True)

30.1.6 [Scripting]: Voltages over 20V in configuring 20V LVTGO-VBS units

If a profile sets any voltage parameter U0 – U7 to be greater than 20V, and the attached

LVTGO-VBS unit is limited to 20V output, then attempting to set the parameter using the

COM interface will fail. This is because automated running does not normally allow the user

the visible feedback on the Voltage Settings form. Note that this includes even “unused”

parameters, such as the maximum voltage parameter when setting a constant voltage. Again,

this is useful for the COM interface, where all the parameter values must be set explicitly, but

less so for the GUI where unused parameters are not visible to the user.

In the unlikely event that the user really wishes to play the specified waveform on a 20V unit

(with the output voltage saturating at 20V), add2 can support removing this restriction.



31 Recommended settings for running the application

The following VISUALCONNX settings are recommended to get the best from the

application..

Application | Use form Navigation Tabs

Application | Hide designer tools during 'Run' mode

Run Time | Freeze of timer when Form not Active : Never

Run Time | Freeze of timer when Form not Visible: True

Window | Fit VISUALCONNX Forms to Project Window (normally ticked)

The effect of the last setting is to keep the forms occupying the same region of the screen.

Strictly, the Project Manager window, which is normally minimised, is used as the model for

the position and size of the other forms. If it is important to see more than one form at once,

or you have a use for re-sizing them, un-tick Fit VISUALCONNX Forms to Project

Window.

The controls on the application's forms may become partly invisible if the form is re-sized.

There is normally no need (and no point) in changing the size of the Project Manager

Window itself. However, you can do this with

Window | Project Manager

to bring up the Project Manager window. The title-bar of the window contains a tick-box

Allow Resizing of Project, which can be ticked.

Other settings should left to their default value.

To access these settings select VISUALCONNX's File | Preferences or click on the Settings

toolbar button.

LVTest VISUALCONNX Application manual LVTest VISUALCONNX Application Version 6.5.0 - bernard 0 0.

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