Rockwell Automation 1746-NR8 SLC 500 RTD/Resistance Input Module User Manual User Manual
Page 78
Publication 1746-UM003A-EN-P
5-6 Ladder Programming Examples
Figure 5.6 Programming for PID Application
ATTENTION
!!!!
When using the module’s scaled-for-PID data format with
the SLC PID function, ensure that the PID instruction
parameters Maximum Scaled S
max
(word 7) and Minimum
Scaled S
min
(word 8) match the module’s minimum and
maximum scaled range, in engineering units, (e.g. -200°C
to +850°C) for each channel. This allows you to accurately
enter the setpoint in engineering units (°C, °F).
First Pass
S:1
15
MOV
Move
Source
Dest
N10:0
0<
O:3.0
0<
I:3.8
11
PID
PID
Control Block
Process Variable
Control Variable
Control Block Length
Setup Screen
N11:0
I:3.0
N11:23
23
END
Use register N10:0 as configuration word for channel 0.
Entering Address N11:0 allocates elements N11:0 to N11:22 for required Control Block file length of 23 words. The Process
Variable is address I:3.0, which stores the value of input data word 0 (channel 0). Output of the PID instruction is stored at
address N11:23 (Control Variable Address).
0000
0001
0002