User Manual Instruction Manual

Publication 1746-UM009B-EN-P - September 2007
Write Ladder Logic 57
3. Enter PID parameters in engineering units into the PID
instruction.
For example, if the 4…20 mA analog input range represents
0…300 PSI, enter 0 as the minimum (Smin) and 300 as the
maximum (Smax). You can also enter setpoints and deadband in
engineering units. The data monitor screen for PID displays its
parameters in the same engineering units.
Ladder Logic
We present two examples of PID control logic with analog I/O scaling
for use on an SLC 5/02 (or later) processor.
• Scaled voltage input and output, 0…10V dc
• Scaled current input and output, 4…20 mA