24400787 LabVIEW Project Report Complete HPK Kumar Detailed

HPK Kum

ar

“VI BASED TEMPERATURE SENSING AND

CONTROLLING USING NI LABVIEW”

HPK Kumar

HPK Kum

ar

ACKNOwlEDGEmENT

HPK Kumar

HPK Kum

ar

ACKNOWLEDGEMENT

First and foremost we wish to express our sincere gratitude and grateful

acknowledgement to our institution, Channabasaveshwara Institute of Technology, for

providing us the opportunity to do our project work.

We take this opportunity to express our sincere thanks and deep sense of gratitude to

our beloved Director, Dr. Suresh Kumar D.S, who is a perennial source of inspiration. His

encouragement and valuable inputs helped us to complete our project successfully.

We take this opportunity to express our profound and sincere gratitude to our beloved

principal, Dr. Pradeep C.R, for facilitating a congenial academic environment in the

college.

Heartfelt thanks to our H.O.D Prof. V.C. Kumar, Department of Electronics and

Communication, for his suggestions in the course of our project work.

We express our immeasurable gratitude to our guide Dr. Suresh Kumar D.S for his

valuable guidance, suggestions and encouragement throughout the project work.

Our sincere thanks to all the staff members of Electronics and Communication

department for their gracious support.

Words are not enough to express our gratitude to our parents, for their moral support

and continuous encouragement.

Last but not the least we thank all our friends and well wishers who have directly or

indirectly helped us during our project work, to make it a great success.

HPK Kumar

HPK Kum

ar

DEDICATED TO

OUR BElOvED

pARENTs

HPK Kumar

HPK Kum

ar

sYNOpsIs

HPK Kumar

HPK Kum

ar

SYNOPSIS

Measuring and control is the quality of every precision Engineering work. Defining

precision and accuracy is of utmost importance in every Engineering concern. A low-cost user-

friendly programmable temperature controller compatible with the PC for industrial purpose

which has to be monitored continuously in a remote place is required in many applications and

it has been designed based on a VI (Virtual Instrument) program with minimum hardware

design.

Presently LabVIEW is fully featured VI programming language produced by NI

(National Instruments). It is a graphical language by which code is constructed and saved

automatically. There is no text-based code like any other programming language, but a

diagrammatic view of how the data flows through the program. Thus LabVIEW is a much

loved tool of the scientists and engineer who can often visualize data flow rather than how a

text based conventional programming language must be built to achieve a task.

The VI program measures and compares deviation between set/measured temperature

values and alerts the user. It can also automatically correct the situation as required by the

control function specified in graphical blocks. The programmable control function may be of

any type like On/Off, P, PI, PD, PID (Proportional Integral Derivative), linear heating, on-

sweep measurement etc. In the meanwhile it provides on-line display of measuring temperature

and plots of the control function output.

HPK Kumar

HPK Kum

ar

CONTENTs

HPK Kumar

HPK Kum

ar

LIST OF CONTENTS

Chapter 1 Introduction .................................................................................................... 1

Chapter 2 Virtual Instrumentation ................................................................................. 4 2.1 Virtual Instrumentation – Introduction ................................................................ .. 5 2.2 Virtual Instrumentation Applications .................................................................... 7 2.3 Integrated Hardware Platform ............................................................................... 8 2.4 The 3 Layers of VI Software ................................................................................. 9 2.5 LabVIEW makes ideal for VI ............................................................................... 9 2.6 Measurement and Control services software ....................................................... 11 2.7 The Philosophy of LabVIEW .............................................................................. 13

Chapter 3 Block Diagram ............................................................................................... 15

3.1 Block Diagram – Introduction ............................................................................. 16 3.2 Block Diagram Description ................................................................................. 17

Chapter 4 Hardware ....................................................................................................... 19

4.1 Hardware – Introduction ..................................................................................... 20 4.2 Hardware Description ......................................................................................... 20

4.2.1 Transducer ................................................................................................ ... 20 4.2.2 Temperature Sensing circuit ......................................................................... 23 4.2.3 Actuator circuit ............................................................................................ 25 4.2.4 Temperature Controllers .............................................................................. 26

Chapter 5 Software ......................................................................................................... 27

5.1 System Program .................................................................................................. 28 5.2 Flow Chart .......................................................................................................... 29 5.3 Front Panel ......................................................................................................... 30 5.4 Block Diagram ................................................................................................ ... 31 5.5 Building Application (.exe) ................................................................................. 32 5.6 Building Installer (setup.exe) .............................................................................. 32 5.7 Remote Controlling ............................................................................................ 33

Chapter 6 Advantages and Applications ....................................................................... 34

6.1 Advantages ......................................................................................................... 35 6.2 Applications ....................................................................................................... 36

Chapter 7 Tests and Results ........................................................................................... 37

Summary ......................................................................................................................... 39 Appendix ......................................................................................................................... 41

Appendix-I AD 590 ............................................................................................. 42 Appendix-II NI ELVIS ......................................................................................... 44 Appendix-III 741 .............................................................................................. 46 Appendix-IV Relays ............................................................................................... 49

Bibliography .................................................................................................................... 51

HPK Kumar

HPK Kum

ar

LIST OF FIGURES & TABLES

Chapter 2 Virtual Instrumentation

2.1.1 Virtual Instrumentation Approach ...................................................................... 5 2.1.2 Functions of Virtual Instruments ........................................................................ 6 2.2.1 Table of Virtual Instrumentation Applications ................................................... 7 2.3.1 The NI Approach – Integrated Hardware Platforms ............................................ 8 2.5.1 LabVIEW VI user Interface and Application Logic .......................................... 10 2.5.2 Virtual Instrumentation Software ..................................................................... 11 2.6.1 Table of NI ...........................................................................-DAQmx features 12 2.7.1 LabVIEW Development Platform .................................................................... 13

Chapter 3 Block Diagram

3.1.1 System Block Digram....................................................................................... 16

Chapter 4 Hardware

4.2.1 AD 590 Packages ............................................................................................. 21 4.2.2 .............................................AD 590 Metallic Package type – Used in Project 21 4.2.3 ......................................................Pin-out and Functional diagram of AD 590 21 4.2.4 741 ..............................................................................................op – amp 23 4.2.5 Trim Po .........................................................................................................t . 23 4.2.6 ............................................................................Temperature Sensing Circuit 24 4.2.7 ...............................................................Block Diagram of the actuator circuit 25 4.2.8 .........................................................................................................Relay ….. 25 4.2.9 .........................................................................................................Heater …. 26 4.2.10 ........................................................................................................Cooler … 26

Chapter 5 Software

5.2.1 Flow Chart ....................................................................................................... 29 5.3.1 Front Panel ...................................................................................................... 30 5.4.1 Block Diagram ................................................................................................. 31 5.7.1 Remote monitoring and controlling of the plant ............................................... 33

Chapter 7 Tests and Results

7.1 .....................................................Tabular Column of Plant’s Controlling Status 38

HPK Kumar

HPK Kum

ar

Chapter 1

INtrODUCtION

HPK Kumar

HPK Kum

ar

V I based Temperature Sensing and Controlling With NI LabVIEW 2008-09

Dept. of ECE, CIT. 2

CHAPTER - I

INTRODUCTION

Any industry will have various parameters that are to be continuously monitored and

controlled from a remote place. In most of the cases the use of manpower becomes almost

impossible and therefore remote monitoring and control systems are extensively developed and

used.

Consider a remote application in a process industry where the temperature of various

sources at different places, need to be monitored and controlled within an acceptable tolerance.

For such an application a low-cost user-friendly programmable temperature controller compatible

with the PC for industrial purpose which has to be monitored continuously in a remote place is

required.

All this features can be implemented easily with low cost by designing a temperature

sensing and controlling unit based on a VI (Virtual Instrument) program with minimum hardware

design to acquire, analyze the data and to initiate the control action accordingly.

VI uses off-the shelf mainstream computer technologies combined with innovative,

flexible software and modular high performance hardware technologies to create a powerful

computer based instrumentation solutions. The objective in Virtual Instrumentation is to use a PC

to mimic real instruments with their dedicated controls and displays, but with the added

versatility that comes with software.

LabVIEW is a graphical programming environment based on the G – programming

language for data acquisition and control, data analysis and data presentation. LabVIEW gives

the flexibility of a powerful programming language without the associated difficulty and

complexity due its graphical programming methodology.

In this project the temperature of a plant at a remote place is acquired, analyzed and

controlled by on/off controller using VI. The temperature to be controlled is acquired using

AD590 temperature sensor having the ability to sense from -550C to 1500C and even up to 2000C

HPK Kumar

HPK Kum

ar



for a short span of time. If the plant requires to sense at higher range than possible by AD590,

then we can just replace the sensing unit by any other higher range temperature sensors.

The design on a VI program minimizes the use of hardware. The hardware design is done

on NI ELVIS (Educational Laboratory Virtual Instrumentation) and DAQ (Data Acquisition)

with the maximum support of software written in NI LabVIEW (Laboratory Virtual

Instrumentation Engineering Workbench).

NI ELVIS is called as general hardware module by National Instruments, which supports

maximum applications. The temperature sensing and controlling on NI ELVIS done here can also

be done, using plenty of other modules manufactured by NI depending on the application area.

But here we have specifically opted NI ELVIS because of its most flexible usage in educational

purpose and projects.

NI ELVIS is connected to DAQ board using a 68 wired cable and the DAQ System is

connected to PC’s PCI (Peripheral Component Interface) slot for PC interaction. This simple

design can be mounted on any higher version PC’s port and does not require any interface add-on

cards or tailoring of the PC’s hardware. That is PC is programmed using LabVIEW to acquire the

temperature from the ELVIS. The control signal generated is given to actuator through Analog

output Channel of ELVIS.

The basic idea is to design web page or an application which provides access to user to

control the process plant parameters through the web. When user login to website with a valid

user ID, user will be able to view the front panel of the control room and it is also possible to

change the parameters according to the applications.

HPK Kumar

HPK Kum

ar

Chapter 2

VIrtUaL

INStrUMeNtatION

HPK Kumar

HPK Kum

ar



CHAPTER - II

VIRTUAL INSTRUMENTATION

2.1 Virtual Instrumentation - Introduction

Virtual Instrumentation uses off-the shelf mainstream computer technologies combined

with innovative, flexible software and modular high-performance hardware technologies to

create powerful computer based instrumentation solutions. The objective in virtual

instrumentation is to use a PC to mimic real instruments with their dedicated controls and

displays with the added versatility that come with software.

Virtual Instrumentation combines hardware and software with industrial standard

computerized technologies to create user-defined instrumentation solutions. National Instruments

specializes in developing plug-in, distributed hardware and driver software for data acquisition

(DAQ), IEEE 488(GPIB), PXI, serial and industrial communications. The driver software is the

application programming interface to the hardware and is consistent across National Instruments

application software, such as LabVIEW, Lab windows and Measurement Studio. These platforms

deliver the sophisticated display and analysis capabilities that Virtual Instrumentation requires.

Fig 2.1.1: Virtual Instrumentation Approach

Virtual Instrumentation can be used to create a complete and customized system for test,

measurement and industrial automation by combining different hardware and software

components. If there is any upgrade required in the process the same system can be used with

some modifications, there is option of extending present components for the further use.

HPK Kumar

HPK Kum

ar



For more than 25 years, National Instruments has revolutionized the way engineers and

scientists in industry, government, academia approach measurement, automation. Leveraging

PCs and commercial technologies, virtual instrumentation increases productivity and lowers

costs for test, control, and design applications through easy-to-integrate software, such as NI

LabVIEW, and modular measurement and control hardware for PXI, PCI, USB, and Ethernet.

With virtual instrumentation, Engineers use graphical programming software to create user-

defined solutions that meet their specific needs, which is a great alternative to proprietary, fixed

functionality traditional instruments. Additionally, virtual instrumentation capitalizes on the ever-

increasing performance of personal computers.

For example, in test, measurement and control, engineers have used virtual

instrumentation to downsize automated test equipment (ATE) while experiencing up to a 10

times increase in productivity gains at a fraction of the cost of traditional instrument solutions.

Last year 25,000 companies in 90 countries invested in more than 6 million virtual

instrumentation channels from National Instruments.

Fig 2.1.2: Functions of Virtual Instruments

National Instruments LabVIEW is an industry-leading software tool for designing test,

measurement, and control systems. Since its introduction in 1986, engineers and scientists

worldwide who have relied on NI LabVIEW graphical development for projects throughout the

product design cycle have gained improved quality, shorter time to market, and greater

engineering and manufacturing efficiency. By using the integrated LabVIEW environment to

interface with real-world signals, analyze data for meaningful information, and share results, we

can boost productivity throughout our organization. Because LabVIEW has the flexibility of a

programming language combined with built-in tools designed specifically for test, measurement

and control. We can create applications that range from simple temperature monitoring to

sophisticated simulation and control systems.

11000111010110011110

Acquire Analyze Present

HPK Kumar

HPK Kum

ar



2.2 Virtual Instrumentation Applications

Virtual instrumentation is applicable in many different types of applications, starting from

design to prototyping and deployment. The LabVIEW platform provides specific tools and

models to solve specific applications ranging from designing signal processing algorithms to

making voltage measurements and can target any number of platforms from the desktop to

embedded devices – with an intuitive, powerful graphical paradigm.

• Design

- Signal and Image Processing

- Embedded System Programming (PC, DSP, FPGA, Microcontroller)

- Simulation and Prototyping And more…..

• Control

- Automatic Controls and Dynamic Systems

- Mechatronics and Robotics And more…..

• Measurements

- Circuits and Electronics

- Measurements and Instrumentation And more…..

Table 2.2.1: VI Applications

With version 8.6, LabVIEW scales from design and development on PCs to several

embedded targets from ruggedized toaster size prototypes to embedded systems on chips.

LabVIEW streamlines system design with a single graphical development platform. In doing so,

LabVIEW encompasses better management of distributed, networked systems because as the

targets for LabVIEW grow varied and embedded, we will need to be able to more easily

distribute and communicate between various LabVIEW code pieces in our system.

The VI can be implemented in normal programming languages like C, C++, Pascal, VB,

VC etc., but the advent of graphic languages (“G” languages) like LabVIEW, HP-Vee, Test point,

Agilent VIEW etc., has made the VI implementation easier.

HPK Kumar

HPK Kum

ar



2.3 Integrated Hardware Platform

Fig 2.3.1: The NI Approach – Integrated Hardware Platforms

A virtual instrument consists of an industry-standard computer or workstation equipped

with powerful application software and cost-effective hardware such as plug-in boards, and

driver software, which together perform the functions of traditional instruments. Virtual

instruments represent a fundamental shift from traditional hardware-centered instrumentation

systems to software-centered systems that exploit the computing power, productivity, display,

and connectivity capabilities of popular desktop computers and workstations.

Although the PC and integrated circuit technology have experienced significant advances

in the last two decades, software truly offers the flexibility to build on this powerful hardware

foundation to create virtual instruments, providing better ways to innovate and significantly

reduce cost. With virtual instruments, engineers and scientists build measurement and automation

systems that suit their needs exactly (user-defined) instead of being limited by traditional fixed-

function instruments (vendor-defined).

HPK Kumar

HPK Kum

ar



2.4 The 3 Layers of Virtual Instrumentation Software

Virtual instrumentation software can be divided into several different layers.

1. Application Software:

Most people think immediately of the application software layer. This is the

primary development environment for building an application. It includes

software such as LabVIEW, Lab Windows/CVI (ANSI C), Measurement

Studio (Visual Studio programming languages), Signal Express and VI Logger.

2. Test and Data Management Software:

Above the application software layer the test executive and data management

software layer. This layer of software incorporates all of the functionality

developed by the application layer and provides system-wide data management.

3. Measurement and Control Services Software:

The last layer is often overlooked, yet critical to maintaining software

development productivity. The measurement and control services layer includes

drivers, such as NI-DAQmx, which communicate with all of the hardware. It

must access and preserve the hardware functions and performance. It also must

be interoperable –it has to work with all other drivers and the many modular I/O

types that can be a part of the solution.

2.5 LabVIEW - Ideal for virtual instrumentation

LabVIEW is an integral part of virtual instrumentation because it provides an easy-to-use

application development environment designed specifically for engineers and scientists.

LabVIEW offers powerful features that make is easy to connect to a wide variety of hardware

and other software. This ease of use and these features deliver the required flexibility for a virtual

instrumentation software development environment. The result is a user-defined interface and

user-defined application functionality. One of the most powerful features that LabVIEW offers is

its graphical programming paradigm. With LabVIEW, engineers and scientists can design

custom virtual instruments by creating a graphical user interface on the computer screen through

which they:

HPK Kumar

HPK Kum

ar



• Operate the instrumentation program

• Control selected hardware

• Analyze acquired data

• Display results

Fig 2.5.1: LabVIEW VI User Interface and Application Logic.

They can customize the LabVIEW user interface, or front panel, with knobs, buttons,

dials, and graphs to emulate traditional instrument control panels of, create custom test panels, or

visually represent process control and operation. Determine virtual instrument behavior by

connecting icons to create block diagrams, which are natural design notations for scientists and

engineers. With graphical programming, engineers and scientists can develop systems more

rapidly than with conventional programming languages, while retaining the power and flexibility

needed to create a variety of applications. LabVIEW is an open environment that includes ready-

to-use libraries for everything from serial, Ethernet, and GPIB communication to motion control,

data acquisition, and image acquisition.

Traditional instrumentation solutions, by nature of their fixed packaging and vendor-

defined nature, can’t rapidly adapt to new software technologies. Because of its inherent

flexibility, virtual instrumentation is much better suited to incorporating new tools and

technology – users can simply upgrade their software, rather than purchase a new system. Over

the 20 plus years of its development, LabVIEW has tightly integrated cutting edge software

HPK Kumar

HPK Kum

ar



technology while still providing a seamless transition from version to version. With the long

project lifetimes often found in the test and measurement industry, it’s critical that LabVIEW

provide a stable platform for development over many decades.

Fig 2.5.2: Virtual Instrumentation software

However, to ensure maximum productivity of its users, LabVIEW must also take

advantage of new technologies as they arise. Many software packages get caught in the trap of

rapid adoption of new technology without regard to longevity. For example, software packages

based primarily on the Microsoft platform of technology over the past 15 years have had several

instances where their software had to be totally redefined due to the discontinuity of the latest

technology, such as COM, ActiveX, and most recently .NET.

LabVIEW has always incorporated and continues to incorporate these technologies to

ensure that the user has access to the latest tools, but integrates them in such a way that there is

no need to completely rework existing code. New technologies, such as .NET, can simply be

added in to existing applications as needed.

2.6 Measurement and control services software

Measurement and control services software is equivalent to the I/O driver software layer.

However, it is much more than just drivers. Though often overlooked, it is one of the most

crucial elements of rapid application development. This software connects the virtual

instrumentation software and the hardware for measurement and control. It includes intuitive

application programming interfaces, instrument drivers, configuration tools, I/O assistants, and

HPK Kumar

HPK Kum

ar



other software included with the purchase of National Instruments hardware. National

Instruments measurement and control services software offers optimized integration with both

National Instruments hardware and National Instruments application development environments.

As an example, National Instruments raised the bar for data acquisition software when it

introduced NI DAQmx for the Windows OS and increased the ease, speed, and power with

which scientists and engineers take measurements. NI DAQmx leverages several technologies

that legacy drivers do not exhibit including multithreading, simplified application programming

interface (API), interactive configuration, and intelligent multi-device synchronization.

Additionally, NI-DAQmx supports broad ranges of programming languages, devices, buses,

sensors, and even mixed signal types. With NI DAQmx, a new user to data acquisition can easily

create an application that leverages parallel processing and synchronizes multiple devices all with

interactive, configuration-based programming.

New Feature Best Good - Not Available

Table 2.6.1: NI-DAQmx with high-performance driver and additional software increase productivity

In addition to new technologies, every copy of NI-DAQmx ships with a collection of

measurement services designed to save data acquisition system developers time and money. This

collection of measurement services, in addition to NI-DAQmx, offer more software value than

any other data acquisition vendor provides with a DAQ device. A few of these measurement

services include, Measurement & Automation Explorer (MAX) for configuring, interacting with,

HPK Kumar

HPK Kum

ar



and testing our hardware; DAQ Assistant for configuration-based creation of data acquisition

tasks; and VI Logger-Lite, FREE software specifically designed for data logging.

2.7 The Philosophy of LabVIEW

LabVIEW is an entirely graphical language which looks somewhat like an Electronic

Schematic diagram on the one hand and a 1950's vintage style electronic instrument on the other

- these are the concepts of the block diagram and the front panel. LabVIEW is hierarchical in that

any virtual instrument that we design (any complete functional unit is called a virtual instrument

and is almost always referred to as a “VI”) can be quickly converted into a module which can be

a sub-unit of another VI. This is entirely analogous to the concept of a procedure in conventional

Programming. LabVIEW is also designed to be extendible. We can add modules through various

means. A manufacturer of an interface card or an instrument may provide us details with a

LabVIEW driver which appears as a VI representing the card and its functionality in the

LabVIEW environment. We can also write a LabVIEW module using LabVIEW and present it as

a VI to be used in other programs (re-usable code) or we can also write modules which interface

with LabVIEW in other languages such as C and C++. These are known as “sub-VIs” and are no

different from VIs except that the interface has been defined to the next level. Sub-VIs in C or

C++ is very useful if we have a complex numerical procedure to perform on the data which is not

covered in a standard LabVIEW routine. Since scientists are rather partial to complex numerical

procedures, this can be a very useful property in our context.

Fig 2.7.1: LabVIEW Development Platform

Programmers develop software applications every day in order to increase efficiency and

productivity in various situations. LabVIEW, as a programming language, is a powerful tool that

can be used to help achieve these goals. Its graphical nature makes it ideal for test and

HPK Kumar

HPK Kum

ar



measurement (T&M), automation, instrument control, data acquisition, and data analysis

applications. This results in significant productivity improvements over conventional

programming languages.

HPK Kumar

HPK Kum

ar

Chapter 3

BLOCK DIaGraM

HPK Kumar

HPK Kum

ar



CHAPTER - III

BLOCK DIAGRAM

3.1 Block Diagram - Introduction

This chapter explains clearly how actually the setup part looks like with the Block

Diagram shown below in fig 3.1.1, which mainly consists of:

• Plant

o Temperature Sensor

o Heater / Cooler

• Sensing Circuit

• NI-ELVIS

• Actuator Circuit

• Personal Computer

• Data Acquisition Module (NI-DAQ)

• NI-LabVIEW Software with NI-ELVIS Driver

Fig 3.1.1: System Block Diagram

Actuator

HPK Kumar

HPK Kum

ar



3.2 Block Diagram Description

3.2.1 Plant:

The remote place at which the temperature is to be monitored and

controlled is considered as a plant. It incorporates a temperature sensor AD590

which acquires live data and submit it to the sensing circuit. The Heater and

Cooler are employed for controlling the varying temperature.

3.2.2 Sensing Circuit:

Temperature sensor AD590 produces a proportional current in accordance

to the temperature in micro amperes. Sensing circuit consists of a widely used op-

amp , which converts current to proportional amplified voltage compatible

with NI-ELVIS.

3.2.3 NI-ELVIS:

NI ELVIS uses LabVIEW-based software instruments and a custom-

designed benchtop workstation and prototyping board to provide the functionality

of a suite of common laboratory instruments. NI ELVIS combines hardware and

software into one complete laboratory suite.

3.2.4 Actuator Circuit:

The actuator is used to switch ON/OFF the Heater/Cooler according to

control signals. A switch is implemented using two relays for Heater and Cooler

respectively.

3.2.5 Personal Computer:

A Personal Computer with Pentium-IV processor to which LabVIEW v8.6

software is loaded is used to monitor, generate control signal and to display

temperature of the plant. A Graphical User Interface (GUI) has been designed

using LabVIEW to interact with plant parameters. The Process parameters, set-

point temperature can be changed through input peripherals according to the

requirement using GUI. The measured temperature of the plant is continuously

displayed on the graph of GUI and the values are tabulated and written in a file to

maintain a Database.

HPK Kumar

HPK Kum

ar



3.2.6 Data Acquisition Module (NI-DAQ):

This NI module interconnects the PC and NI-ELVIS through a 68 wired

cable. NI-DAQ is connected to PCI slot of the computer. This simple design can

be mounted on any higher version PC’s port and does not require any interface

add-on cards or tailoring of the PC’s hardware.

3.2.7 NI-LabVIEW Software with ELVIS Driver:

LabVIEW provides a powerful graphical programming tool for test and

measurement (T&M), automation, instrument control, data acquisition, and data

analysis applications. NI-ELVIS Driver software makes LabVIEW to interact with

hardware by installing ELVIS compatible software library to LabVIEW

installation parent folder.

HPK Kumar

HPK Kum

ar

Chapter 4

harDWare

HPK Kumar

HPK Kum

ar



CHAPTER - IV

HARDWARE

4.1 Hardware – Introduction

System Hardware consists of the following units:

• Transducer (Temperature Sensor - AD590) • Temperature Sensing Circuit

o op-amp o Trim Potentiometer

• Actuator Circuit o Relays

• Temperature Controllers o Heater o Cooler

4.2 HARDWARE DESCRIPTION

4.2.1 Transducer

A transducer is a mechanism or an element of the sensor that transforms the energy

associated with, what is being measured into useful form of energy (Electrical energy).

In this project, AD 590 M-series is used as the temperature sensor which converts

temperature into electrical signal. The features of this transducer are as follows:

• Linear current output : 1 µA/0

• Wide temperature range : −55°C to +150°C

K

• 2 - terminal device : voltage in/current out

• Wide power supply range : 4 V to 30 V

• Excellent linearity : ±0.3°C over full range (AD590M)

• Laser trimmed to ±0.5°C calibration accuracy (AD590M)

• Sensor isolation from case

HPK Kumar

HPK Kum

ar



Fig 4.2.1: AD 590 Packages

Fig 4.2.2: AD590 Metallic Package type (Used in Project)

AD 590 Description:

The AD590 is an integrated-circuit temperature transducer which produces an output

current proportional to the absolute temperature. The device acts as a high impedance constant

current regulator, passing 1 µA/ 0K for supply voltages between +4V and +30V. Laser trimming

of the chip's thin film resistors is used to calibrate the device to 298.2 µA output at 298.20K

(250

C).

Fig 4.2.3: Pin-out and Functional diagram of AD 590

HPK Kumar

HPK Kum

ar



The AD590 should be used in any temperature-sensing application between to

in which conventional electrical temperature sensors are currently employed. The

inherent low cost of a monolithic integrated circuit combined with the elimination of support

circuitry makes the AD590 an attractive alternative for many temperature measurement situations.

Linearization circuitry, precision voltage amplifiers, resistance measuring circuitry and cold

junction compensation are not needed in applying the AD590. In the simplest application, a

resistor, a power source and any voltmeter can be used to measure temperature.

In addition to temperature measurement, applications include temperature compensation

or correction of discrete components, and biasing proportional to absolute temperature.

The AD590 is particularly useful in remote sensing applications. The device is insensitive

to voltage drops over long lines due to its high-impedance current output. Any well insulated

twisted pair is sufficient for operation hundreds of feet from the receiving circuitry. The output

characteristics also make the AD590 easy to multiplex: the current can be switched by a CMOS

multiplexer or the supply voltage can be switched by a logic gate output.

AD 590 Highlights:

1. The AD590 is a calibrated two terminal temperature sensor requiring only a dc voltage

supply (+4 V to +30 V). Costly transmitters, filters, lead wire compensation and

linearization circuits are all unnecessary in applying the device.

2. State-of-the-art laser trimming at the wafer level in conjunction with extensive final

testing ensures that AD590 units are easily interchangeable.

3. Superior interface rejection results from the output being a current rather than a voltage.

In addition, power requirements are low (1.5 mW at 5V at +25°C.) These features make

the AD590 easy to apply as a remote sensor.

4. The high output impedance (>10 MW) provides excellent rejection of supply voltage drift

and ripple. For instance, changing the power supply from 5 V to 10 V results in only a 1

µA maximum current change, or 1°C equivalent error.

5. The AD590 is electrically durable: it will withstand a forward voltage up to 44 V and a

reverse voltage of 20 V. Hence, supply irregularities or pin reversal will not damage the

device.

HPK Kumar

HPK Kum

ar



4.2.2 Temperature Sensing Circuit

Temperature sensor AD590 produces a proportional current in accordance to the

temperature in micro amperes. Sensing circuit consists of a widely used op-amp µA 741, which

converts current to proportional amplified voltage compatible with NI-ELVIS.

µA 741 - Operational Amplifier:

The µA 741is a high performance monolithic operational

amplifier constructed on a single silicon chip. It is intended for a

wide range of analog applications.

• Summing amplifier

• Voltage follower

• Integrator

• Active filter

• Function generator

The high gain and wide range of operating voltages provide

superior performances in integrator, summing amplifier and general

feedback applications. The internal compensation network (6dB/octave) insures stability in

closed loop circuits.

Potentiometer:

Fig 4.2.5: Trim Pot

Trim type potentiometer is manually adjustable, variable, electrical resistor. It has a

resistance element that is attached to the circuit by three contacts, or terminals. The ends of the

resistance element are attached to two input voltage conductors of the circuit, and the third

contact, attached to the output of the circuit, is usually a movable terminal that slides across the

resistance element, effectively dividing it into two resistors. Since the position of the movable

terminal determines what percentage of the input voltage will actually be applied to the circuit,

Fig 4.2.4: µA 741 Op-amp

HPK Kumar

HPK Kum

ar



the potentiometer can be used to vary the magnitude of the voltage; for this reason it is

sometimes called a voltage divider. Typical uses of potentiometers are in radio volume controls

and television brightness controls.

The resistor R1

Fig 4.2.6: Temperature Sensing Circuit

Circuit Description:

The temperature sensor AD 590’s positive terminal is connected to the virtual ground of

the op-amp. As the AD590 produces proportional current in µA, op-amp input current at non-

inverting terminal is to be calibrated at desired current value by adjusting R

present in the sensing circuit needs to be varied precisely for the current

calibrations. Hence, a trim pot of 10 KΩ is used in series with the constant 10 KΩ resistor.

Circuit Diagram:

1.

Calculations:

273 µA at 0 0C (273 0K)

R1= V/273 µA = 18.31 K Ohms

Input Voltage, V = +5V

Now if we should get Vout = 28 mV at 28 0C,

Then, Rf

The circuit is trimmed by adjusting R

= 28mV/28 µA = 1 K Ohms

1 for a 0 mV output with the AD590 at 0°C. Rf is

then adjusted for 100 mV out with the sensor at 100°C. Other calculation pairs of temperatures

may be used with this procedure as long as they are measured accurately by a reference sensor.

Note that for 150 mV output (150°C) the V+ of the op-amp must be lesser than +17V and greater

+

-

V-

V+

HPK Kumar

HPK Kum

ar



than +13V. Also note that V− should be at least −4V; if V− is ground, there is no voltage applied

across the device.

The temperature proportional output voltage of the sensing circuit is given to the analog

channel of the NI-ELVIS to sense the plant temperature.

4.2.3 Actuator Circuit

After sensing of the temperature and its manipulation by LabVIEW, the digital ON/OFF

control signal for the Heater/Cooler is generated and given to hardware through NI-ELVIS. The

control signal is of low level DC voltage and Controllers operate on high AC voltages. Hence,

the control from one level to another is given by actuator circuit using relays.

Fig 4.2.7: Block Diagram of the Actuator Circuit

Relay:

It is an electromechanical device to control the high

level ac voltages using a TTL logic voltage levels. Relays

are components which allow a low-power circuit to switch

a relatively high current on and off, or to control signals

that must be electrically isolated from the controlling circuit

itself.

To make a relay operate, we have to pass a suitable

‘pull-in’ and ‘holding’ current (DC) through its energizing coil. Generally relay coils are

designed to operate from a particular supply voltage - often 12V or 5V, in the case of many of the

Fig 4.2.8: Relay

HPK Kumar

HPK Kumar

Typewritten Text

HPK Kumar

Typewritten Text

HPK Kum

ar



small relays used for electronics work. In each case the coil has a resistance which will draw the

right pull-in and holding currents when it’s connected to that supply voltage. So the basic idea is

to choose a relay with a coil designed to operate from the supply voltage we are using for our

control circuit (and with contacts capable of switching the currents we want to control), and then

provide a suitable ‘relay driver’ circuit so that our low-power circuitry can control the current

through the relay’s coil. Typically this will be somewhere between 25mA and 70mA.

4.2.4 Temperature Controllers

The plant temperature is compared with the set-point temperature and output is given to a

control element through NI-ELVIS. In this project LabVIEW is used to implement the ON/OFF

controller, the high level voltage on which controllers work are produced by the actuator circuit

using the low level voltage logic from LabVIEW / NI-ELVIS.

Here the controller is providing mainly 3 functions:

1. Provide one to one correspondence of the output.

2. Eliminate the offset produced.

3. Handle the fast process load changes.

Heater:

If the temperature of plant is below the set point temperature

then heater will gets on and increases the temperature of liquid in the

system. The coil type heater of 300W power, working at 230V AC/DC

is used in the project, which is having the capability of heating the

liquid in the system rapidly and having the feature of corrosion free

material. The 230V AC is given by the actuator circuit as per the

controlling signals produced by LabVIEW.

Cooler:

If the temperature of plant is above the set point

temperature then cooler will gets on and decreases the

temperature of liquid in the system. Cooler also works by the

same control mechanism as control signals given to heater.

Fig 4.2.9: Heater

Fig 4.2.10: Cooler

HPK Kumar

HPK Kum

ar

Chapter 5

SOFtWare

HPK Kumar

HPK Kum

ar



CHAPTER - V

SOFTWARE

5.1 System Program

Temperature Sensing and Controlling is done by Graphical programming language

written in LabVIEW v8.6. This type of programming give rise to virtual instruments which

mimics the real hardware without actually using it.

VIs when created popup two windows:

1. Front Panel:

Front Panel window is the interface to the VI code, containing visual waveform

charts, knobs, switches, indicators, tables and all other virtual things needed for easy

interaction with the project designed.

2. Block Diagram:

Block Diagram window contains graphical program code such as icons of

different functionalities, wires, loops, sequences, structures, conditions, data and all

the things needed for programming graphically. If LabVIEW does not contains the

graphical code required for us, then it can be created by our self easily by graphical

codes provided by LabVIEW itself or even by other programming languages, without

actually using that particular software.

In this project, software will get the sensed temperature details from NI-ELVIS after

which, it will be manipulated and shown in all 3 formats, that is in degree Celsius, Kelvin,

Fahrenheit for ease of use by any user and also the readings will be plotted on the graph to

observe the variations of temperature with respect to time and at the same time the acquired

temperature reading will be tabulated and stored in database for every specified time interval

given by the user, which helps to keep records of temperature continuously.

After sensing the data, the next immediate part of the program is controlling, that is to

keep the system temperature constant as specified in the field of ‘set point temperature’ by user,

HPK Kumar

HPK Kum

ar



means if the sensed temperature reading is below the ‘set point temperature’ then the control

signal is given to heater to turn-on, and at the same time to turn-off the cooler. If the sensed

temperature reading is above the ‘set point temperature’ then the control signal is given to heater

to turn-off, and at the same time to turn-on the cooler. The method of controlling action

explained is called ‘ON-OFF Controlling’.

5.2 Flowchart:

The flowchart of the Graphical programming language designed in LabVIEW for the

above sensing and controlling action is shown below:

Fig 5.2.1: Flow Chart of the Project

HPK Kumar

HPK Kum

ar



5.3 Front Panel

Fig 5.3.1: Front Panel of the Project

The Front Panel which is having capable of providing flexible interaction to users is

shown in fig. 5.3.1. All input, intermediate and output status are available on front panel.

In this project,

The inputs are:

• Set Point Temperature

• Controlling Type

• Reset for Controlling

• Delay between each Execution

• Tabulation Controls

• Stop Execution

The outputs are:

• Temperature Readings

• Its Graphical Indicator

• Heater Condition

• Cooler Condition

• Tabular Column

• Current date/time for database

The set point and controlling type can be given according to the application by user.

Virtual Indicators are used to show heater and cooler’s condition. Tabulation will help in

observing readings.

HPK Kumar

HPK Kum

ar



5.4 Block Diagram

Fig 5.4.1: Block Diagram of the Project

HPK Kumar

HPK Kum

ar



The block diagram which contains graphical programming code is shown in fig. 5.4.1.

Acquisition of temperature data, manipulating it, generating corresponding control signals,

storing to database, sending control signals to hardware, to execute the program as specified by

the delay given by user and everything that comes under the programming part will be done by

the graphical blocks and wires shown in the block diagram.

5.5 Building Application (.exe)

Building stand alone application is a method in LabVIEW for constructing the software

part which works independent of NI-LabVIEW installed in PC, but it will be the final part of the

project where we cannot get the Block Diagram window to alter the graphical LabVIEW

program. It will be helpful to designers who can sale their software in which user cannot change

the program, but can use it.

Steps used in this project for building application:

• Construct all VI’s needed for the final project (.vi).

• Link all those VI’s with in a project file (.lvproj).

• Build library for the corresponding project (.lvlib) – optional step, but preferred.

• Verify each and every links and set the main VI for user interaction.

• Construct Application, by giving icons and key requirements to it.

5.6 Building Installer (setup.exe)

Application may need hardware driver software to be installed in the PC, but building

installer is like designing complete software itself for building the project without the need of any

driver software pre-installed in PC. All the steps involved in building application is needed, after

which all the hardware drivers required are to be attached to the project and installer is build by

giving right license file, readme file, icon file, installer key, project designer details and all other

requirements. After building, installer can be provided to users, who can work with the designed

project, even without a single pie of knowledge in LabVIEW.

HPK Kumar

HPK Kum

ar



5.7 Remote Controlling

Either Application or installer of the final project is installed using ‘setup.exe’ on

controlling system attached to plant and also to the remote system. Connection can be created by

internet/WAN/MAN/LAN or any kind of standard connectivity between the two system

software’s.

Fig 5.7.1: Remote monitoring and controlling of the plant

Then main system at the plant area is set to be as master. Remote system can login to

master by valid authentication and can view or control the status of plant’s temperature according

to the type of authentication given. On either side of the PC’s screen we can look the front panel

(only), through controlling can be done easily.

HPK Kumar

HPK Kum

ar

Chapter 6

advantages &

appliCations

HPK Kumar

HPK Kum

ar



CHAPTER - VI

ADVANTAGES AND APPLICATIONS

6.1 Advantages

• Complete analysis and flexible manipulation of the acquired temperature.

• Save development time.

• Graphical and Numerical Display of acquired data.

• Reduces maintenance cost.

• Increase Performance.

• Reuse of external code.

• Easy Tabulation and maintenance of records by Database of Acquired Data.

• Different controlling options viz Heater/Cooler can be used based on application.

• Application and Installers can be built.

• Remote controlling of the plant provides an easy access to the user.

• Flexible options for improving productivity.

HPK Kumar

HPK Kum

ar



6.2 Applications

• In industrial plants

• Reactors (Nuclear, Thermal, Atomic)

• Automobiles

• Robotics

• Embedded Systems

• Structural Health Monitoring

• Environmental Monitoring

• Medical Field

……. Approximately in all fields.

HPK Kumar

HPK Kum

ar

Chapter 7

teStS & reSultS

HPK Kumar

HPK Kum

ar



CHAPTER - VII

TESTS AND RESULTS

This project demonstrates the acquisition of temperature, measurement, analysis and

controlling using virtual instrumentation. Various tests were conducted during the development

and the final stages of the system design. The results obtained are satisfied with accuracy.

The obtained results are tabulated below; here we can easily compare the system

temperature read by the temperature sensor with the set point temperature to be obtained in the

system with respect to the time.

Sl.

No.

Time

(in sec)

Set Point

Temperature

System

Temperature

Heater

Condition

Cooler

Condition

1. 0 60 26.321 ON OFF

2. 5 60 30.124 ON OFF

3. 10 60 33.526 ON OFF

4. 20 60 39.510 ON OFF

5. 30 60 45.685 ON OFF

6. 40 60 51.621 ON OFF

7. 50 60 56.780 ON OFF

8. 60 60 59.813 ON OFF

9. 70 60 60.923 OFF ON

10. 80 60 60.105 OFF ON

11. 90 60 59.941 ON OFF

12. 100 60 60.735 OFF ON

13. 110 50 58.387 OFF ON

14. 120 50 56.916 OFF ON

15. 130 50 55.032 OFF ON

Table 7.1: Plant’s Controlling Status up to 130 sec.

HPK Kumar

HPK Kum

ar

SUMMARY

HPK Kumar

HPK Kum

ar



SUMMARY

The temperature sensing and controlling system using LabVIEW is designed and listed

with repeated measurements and the performance was satisfactory.

The following conclusion can be drawn from the performance results:

• The overall project has gained a lot of importance as the data acquisition can be

done from a remote place, which saves wiring and maintenance cost.

• Graphical Programming is simple and flexible.

• Program can be changed easily based on the user requirements.

• Heater and cooler controlling options can be used depending on the applications.

• The tabulation and storing of details in a database makes a good work for keeping

record of the system.

The following suggestions are made for future development and further improvements of

the presented project:

• Different kind of controllers like P, PI, PD and PID can be implemented.

• The number of parameters to be measured can be increased like measuring of

pressure and other parameters.

• Status of the temperature can be sent and controlled via e-mail and SMS after

validating the user.

HPK Kumar

HPK Kum

ar

APPENDIX

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

Appendix I – AD 590

Wiring Configuration

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

Appendix II - NI ELVIS

NI ELVIS uses LabVIEW-based software instruments and a custom-designed benchtop

workstation and prototyping board to provide the functionality of a suite of common laboratory

instruments.

NI ELVISmx is the software that supports NI ELVIS II hardware. It provides the following

LabVIEW soft front panels (SFPs):

• Arbitrary Waveform Generator (ARB)

• Bode Analyzer

• Digital Reader

• Digital Writer

• Digital Multimeter (DMM)

• Dynamic Signal Analyzer (DSA)

• Function Generator (FGEN)

• Impedance Analyzer

• Oscilloscope (Scope)

• Two-Wire Current Voltage Analyzer

• Three-Wire Current Voltage Analyzer

• Variable Power Supplies

NI ELVIS Hardware

NI ELVIS combines hardware and software into one complete laboratory suite. Figure

shows a typical diagram of an NI ELVIS II system.

Fig: Typical NI ELVIS System

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

NI ELVIS Benchtop Workstation

The workstation control panel provides easy-to-operate knobs for the variable power

supplies and function generator, and offers convenient connectivity and functionality in the form

of BNC and banana-style connectors to the function generator, scope, and DMM instruments. Figure shows the control panel parts locator diagram.

Fig: Top View of NI ELVIS II Benchtop Workstation with Prototyping Board

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

Appendix III –

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

Appendix IV – Relays

It is an electromechanical device to control the high

level ac voltages using a TTL logic voltage levels. Relays

are components which allow a low-power circuit to switch

a relatively high current on and off, or to control signals

that must be electrically isolated from the controlling

circuit itself.

To make a relay operate, you have to pass a suitable ‘pull-in’

and ‘holding’ current (DC) through its energizing coil. Generally relay

coils are designed to operate from a particular supply voltage - often

12V or 5V, in the case of many of the small relays used for electronics

work. In each case the coil has a resistance which will draw the right

pull-in and holding currents when it’s connected to that supply voltage.

So the basic idea is to choose a relay with a coil designed to operate

from the supply voltage you are using for your control circuit (and with contacts capable of

switching the currents you want to control), and then provide a suitable ‘relay driver’ circuit so

that your low-power circuitry can control the current through the relay’s coil. Typically this will

be somewhere between 25mA and 70mA.

Relay Design ID: Relays are either Normally Open or

Normally Closed. Notice the position of the

switches in the two relays shown below.

Normally open relays have a switch that

remains open until energized (ON) while

normally closed relays are closed until

energized. Relays are always shown in the

de-energized position (no current flowing

through the control circuit – OFF).

HPK Kumar

HPK Kum

ar



APP

END

IX: C

ASE

STU

DY

Normally Open Relays:

Normally Closed Relays:

DE-ENERGIZED (OFF) ENERGIZED (ON)

HPK Kumar

HPK Kum

ar

BIBLIOGRAPHY

HPK Kumar

HPK Kum

ar



BIBLIOGRAPHY

1) ‘NI Educational Laboratory Virtual Instrumentation Suite mx (NI ELVIS™ mx)

User Manual’ by National Instruments.

2) ‘LabVIEW™ User Manual’ April 2003 Edition, Part Number 320999E-01. ©1992–

2003 National Instruments Corporation. All rights reserved.

3) ‘Two Terminal IC Temperature Transducer, AD 590’ Datasheet © 2003 by

Analog Devices, Inc. USA.

4) ‘Introduction to LabVIEW – Graphical Programming for Engineers and

Scientists’ by National Instruments.

5) ‘LabVIEW 8.6 User manual, Measurement & automation, National Instruments

Inc. (2008).

6) ‘LabVIEW: Advanced Programming Techniques’, 2nd

7) ‘LabVIEW in Digital Signal Processing and Digital Communication’, 2

Edition, by Rick Bitter

(Motorola), Taqi Mohiuddin (Mindspeed Technologies), Matt Nawrocki (Motorola).

nd

8) ‘LabVIEW Exercises’, by A. Fakheri.

Edition,

by Corry. L. Clark.

9) ‘Image Processing with LabVIEW™ and IMAQ™ Vision’ by Thomas Klinger

Thomas, Ph.D., © 2003 Pearson Education Inc.

10) ‘http://www.ni.com’ by National Instruments.

11) ‘G Programming Reference Manual’ Part Number 321296B-01, by National

Instruments, 1998.

12) ‘Getting Started for LabVIEW with Data Acquisition’, by National Instruments.

13) ‘A Software Engineering Approach to LabVIEW’ by Jon Conway • Steve Watts.

HPK Kumar

http://www.informit.com/safari/author_bio.asp@ISBN=0130474150

HPK Kum

ar



14) ‘Introduction to LabVIEW™

15) ‘LabVIEW™ Fundamentals’ August 2005 Edition, Part Number 374029A-01.

©2005 National Instruments Corporation. All rights reserved.

Six-Hour Course’ September 2003 Edition, Part

Number 323669B-01, © 2003 National Instruments Corporation.

16) ‘Sensors, Transducers, and LabVIEW’ by

17) ‘LabVIEW Help’, LabVIEW

Barry Paton.

--

18) ‘Learning LabVIEW 8.6 Video Toolkit’, by National Instruments Corporation.

> Help, “Help and Examples”.

19) ‘LabVIEW™ Quick Reference Card’, ©2006 National Instruments Corporation.

20) ‘Using External Code in LabVIEW’, by National Instruments Corporation.

21) ‘LabVIEW Signal Processing’

22) ‘Analog Electronics with LabVIEW’ by

by Mahesh L. Chugani • Abhay R. Samant • Michael

Cerra.

Kenneth L. Ashley

23) ‘Hands-On Exercise Manual for LabVIEW Programming, Data Acquisition, and

Analysis’ by

.

24) ‘LabVIEW for Electric Circuits, Machines, Drives, and Laboratories’

Jeffrey Y. Beyon.

25) ‘NI LabVIEW Database Connectivity Toolset User Manual’, http://www.ni.com/pdf/manuals/321525c.pdf

by Nesimi

Ertugrul.

HPK Kumar

24400787 LabVIEW Project Report Complete HPK Kumar Detailed

Documents

Transcript of 24400787 LabVIEW Project Report Complete HPK Kumar Detailed