Software of Programmable Controllers

1. Slovak University of Technology Faculty of Material Science and Technology in Trnava Software of ProgrammableControllers 2007

2. 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...

3. KRGN 90 - operator interface • Displays • DATA - VALUE • Set Point • PROCESS • OUTPUT • ALARMS

4. KRGN 90 - operator interface • Keys • Set Point • MAN, AUTO, CAS • Man Reset • PP, II, DD • ACK

5. KRGN 90 - eng. functions • Displays • Object - step - function - data - value • AI configuration • CONF / AUX - ANAL • Loop configuration • CONF / AUX - LOOP • INS - RPL - DEL

6. 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

7. 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

8. 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,...

9. 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

10. 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

11. 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

12. FNC 20 - PID function FNC 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

13. 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

14. FNC 22 – Auto RATIO • On line computation of the slave loop RATIO for a bumpless switching the AUTO mode to the CAS one • Q1 – signal source specification

15. 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

16. 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

17. FNC 30- arithmetic operations • Arithmetic operations: sum, difference, multiplication and division. • Q1 – the second operand • Q2 – type of arithmetic operation • Q3 – order of operands

18. 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.

19. 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.

20. 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

21. 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

22. Auxiliary parameters for AI • ISFL – input safety lower value • ISFL – input safety lower value • SAFE - safety/ default value of input signal

23. 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

24. 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

25. 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