I am trying to get two PID loops to track each other. The PLC I am using PLC 5, cannot do this. Does any PLC stub have feedback from another loop as an input. Discrete controllers do but I can't find a PLC that does.
Modicon has it with their PID2 instruction. This is available with ProWorx NxT software. I've used it many times and also have been confounded by its lack of availability in other PLC products.
David Wiseman wrote, "I am trying to get two PID loops to track each other. The PLC I am using PLC 5, cannot do this. Does any PLC stub have feedback
from another loop as an input. Discrete controllers do but I can't find a PLC that does."
The Enhanced PID instruction built into the Function Block Diagram editor for Rockwell Automation's ControlLogix product has built-in support for this capability.