Software of Programmable Controllers
description
Transcript of Software of Programmable Controllers
Software of Programmable Controllers
Slovak University of TechnologyFaculty of Material Science and Technology in Trnava
2007
Programmable controller KRGN 90 8 - loop controller HW configurable I/O signal more than 40 pre-programmed functions operator panel
operator interface engineering functions
4 displays to monitor a controlled processes communication protocol...
KRGN 90 - operator interface
Displays
DATA - VALUE Set Point PROCESS OUTPUT ALARMS
KRGN 90 - operator interface
Keys
Set Point MAN, AUTO, CAS Man Reset PP, II, DD ACK
KRGN 90 - eng. functions
Displays Object - step - function - data - value
AI configuration CONF / AUX - ANAL
Loop configuration CONF / AUX - LOOP
INS - RPL - DEL
Analogue input configuration
CONF - ANAL- AInn FNC 01 - Q1, Q2, Q3, Q4...
AUX - ANAL - Ainn DFIL, ISCL, ISCH IALL, IALH, ISFL, ISFH, SAFE
ANAL - Ainn AI type assignment to the physical AInn
Loop configuration CONF - LOOP- l
FNC 10, FNC 20, FNC 55
AUX - LOOP - l SCAN, OLIL, OLIH, OGRL, OGRH LSCL, LSCH, GRAD PALL, PALH, DALL, DALH DINL, DINH, GAPL, GAPH...
LOOP ON / OFF
Loop program structure Controller KRGN 90 has 8 LOOPs
Loop has 20 program STEPs maximum
Program step consists one function FNCnn
Function has questions Q1,Q2, Q3,...
FNC 01 - AI processing
Purpose: The unified analogue signal transformation to digital representation in e.u. and primary input variable processing.
Q1 – a type of current unified input signal
Q2 – linearisation type
Q3 – binary output for technological alarm signalisation
Q4 – safety alarm signalisation
FNC 10 - step signal specification
An value assignment to the real and logical part of program step output, where the function FNC 10 is configured.
Q1 – real part of the program step value
Q2 – logical part of the program step specification
FNC 20 - PID function
The ideal paralel type of a PID algorithm as a sum of the proportional, integral and derivative part of a control action.
Q1– the type of the set point processing when a loop is switched from MAN to AUTO mode.
Q2 – control action direction
Q3 – loop mode after controller restart
FNC 20 - PID functionFNC 20 continued:
Q4 – type of the derivative part of control action
Q5 – binary variable address for process variable alarm
Q6 – binary vaariable address for deviation alarm
Q7 – control action computation type
FNC 21 – Set Point computation for cascade loop
A computation of the set point for a slave loop in cascade mode.
A set point of the cascade loop is computed according the expression
ZHCAS = RATIO*INPUT+BIAS
Q1 – signal source specification
FNC 22 – Auto RATIO
On line computation of the slave loop RATIO for a bumpless switching the AUTO mode to the CAS one
INP
BIASZHCASRATIO
Q1 – signal source specification
FNC 23 – Auto BIAS
On line computation of the slave loop BIAS for a bumpless switching the AUTO mode to the CAS one
Q1 – signal source specification
INPUT*RATIOZHCASBIAS
FNC 24 - SP computation for slave loop
A set point computation for a cascade loop, when the limits of this set point are given.
Q1 – loop number
LSCLLSCH*n
DOUT1n
ZHCASn
ZHCAS
FNC 30- arithmetic operations
Arithmetic operations: sum, difference, multiplication and division.
Q1 – the second operand
Q2 – type of arithmetic operation
Q3 – order of operands
FNC 50 – Dynamic signal compensation
Dynamic compensation of a signal by the block LEAD/LAG of 1st order.
Q1 – lead time constant in the interval 0 to 99999 sec.
Q2 – lag time constant in the interval 0.5 to 99999 sec.
isT1dsT1
F(s)
FNC 51 – Dead Time Block
A delay of a main value signal at a specified time.
Q1 – time delay in the interval 0.5 to 99999 sec.
sDeF(s)
FNC 55 – D/A conversion
A conversion of a control action value to the corresponding analogue unified signal.
Q1 – type of analogue current unified signal
Q2 – signal specification
Auxiliary parameters for AI
DFIL – the time constant of 1st. order digital filter
ISCL – input scale lower
ISCH – input scale upper
IALL – lower limit for technological alarm
IALH – upper limit for technological alarm
Auxiliary parameters for AI
ISFL – input safety lower value
ISFL – input safety lower value SAFE - safety/ default value of input signal
Auxiliary parameters for LOOP
SCAN – program loop execution scan period
OLIL – lower limit of control action
OLIH – upper limit of control action
OGRL – maximum rate of valve closing rate during one scan period
OGRH – maximum rate of valve opening rate during one scan period
Auxiliary parameters for LOOP continued
GRAD – maximum rate of set point change during one
scan period
LSCL – lower limit of set point
LSCH – upper limit of set point
PALL – lower limit of process variable alarm
PALH – upper limit of process variable alarm
DALL – lower limit of deviation alarm
DALH – upper limit of deviation alarm
Auxiliary parameters for LOOP continued
DINL – deviation lower limit indicated on the bargraph
DINH – deviation upper limit indicated on the bargraph
GAPL – lower hysteresis band for control action execution
GAPH – upper hysteresis band for control action execution