Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 223)

EAF
Process Control Instructions
Chapter 16
16-12
Entry and Display of a PID Control Instruction
The following example programs show how to use the PID EAF.
Figure 16.3 and the associated rung description give a detailed explanation
of the basic sections of a PID program. We recommend that you study this
example thoroughly before proceeding to the other example programs.
The three programs that follow were programmed specifically for 1771-IF
and 1771-OF modules.
Figure 16.3 shows how you can enter a ladder diagram in the main
program and execute a PID function.
Figure 16.3
PID Ladder Diagram for Loops with a Minimum Update Time of 200ms
EN BLOCK XFER READ
DATA ADDR:
MODULE ADDR:
BLOCK LENGTH:
FILE: 0030
110
02
0375Ć0376
DN
EN FILE TO FILE MOVE
COUNTER ADDR:
POSITION:
FILE LENGTH:
0045
001
009
FILE A:
FILE R:
RATE PER SCAN
0300-0310
0311-0321
009
DN
045
15
045
15
RUNG 1
111
07
011
07
TON
0045
.01
EXECUTE AUX
FUNCTION NUMBER:
DATA ADDR:
RESULT ADDR: 27
0300
0350
111
07
0375
480
G
0376
750
G
PR 009
AC 001
FUNCTION
0045
17
0045
15
EN BLOCK XFER READ
DATA ADDR:
MODULE ADDR:
BLOCK LENGTH:
FILE: 0031
120
01
0350-0350
DN
112
06
012
06
RUNG 2
RUNG 3
RUNG 4
RUNG 5