Slovak University of Technology
Faculty of Material Science and Technology in Trnava
Software of
Programmable
Controllers
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

AI configuration
 CONF

/ AUX - ANAL
Loop configuration
 CONF

- step - function - data - value
/ 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 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
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
RATIO 

ZHCAS  BIAS
INP
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
BIAS  ZHCAS  RATIO * INPUT

Q1 – signal source specification
FNC 24 - SP computation for
slave loop

A set point computation for a cascade
loop, when the limits of this set point are
given.
ZHCAS

n
 ZHCAS
 DOUT * LSCH  LSCL 
n 1
n
Q1 – loop number
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.
F(s) 
1  sTd
1  sTi

Q1 – lead time constant in the interval 0 to 99999
sec.

Q2 – lag time constant in the interval 0.5 to 99999
sec.
FNC 51 – Dead Time Block

A delay of a main value signal at
a specified time.

sD
F(s)  e

Q1 – time delay in the interval 0.5 to 99999 sec.
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 –
ISFL –
 SAFE 
input safety lower value
input safety lower value
safety/ default value of input signal
Auxiliary parameters for
LOOP

SCAN –

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
program loop execution 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