Rockwell Automation 1746-INT4 Thermocouple/MV Isolated/ User Manual - Manual (Page 62)

Publication 1746-UM614B-EN-P - September 2007
62 Ladder Programming Examples
Process a Channel Input
with the PID Instruction The module was designed to input a channel directly to a PID
instruction of an SLC 5/02 processor or later without the need of an
intermediate scale operation.
Use channel data as the process variable for the PID instruction.
1. Select scaled-for-PID as the data type in the channel
configuration word.
2. Specify channel data word as the process variable for the PID
instruction.
In this example, the value 2081 is the numeric equivalent of
configuration word N10:0 for channel 0. It is configured for a type K
thermocouple, scaled-for-PID, zero the signal for an open input, °C,
and channel enabled.
Program
EXAMPLE
Use channel data as the process variable for the PID
instruction.
] [ MOVE
Source
N10:0
2081
Dest O:3.0
0
S:1
15
MOV
11
] [
I:3.4
PID
PID
Control Block
N11:0
Process Variable I:3.0
Control Variable N11:23
Control Block Length 23
SCL
SCALE
Source
N11:23
Rate [/10000]
Offset
Dest
END
Rung 2:0 First Pass Bit
Channel 0 Status Rung 2:1
Rung 2:2
Rung 2:3 Rate and Offset values depend on your application. The Destination will typically be an
analog output channel. For specific examples of the SCL instruction, refer to the Analog I/O
Modules User Manual.
Initialize Channel 0