Being new to PID loops, so far all my research says that you have to have an I/O Unit configured to use a PID loop. What I am trying to do is create a PID loop in PAC Control Professional ver R9.6d that does NOT need an I/O Unit. We are reading data from Modbus TCP. So the inputs will come from Modbus TCP registers.
From what I can tell, the only way to configure a PID loop is to first add an I/O Unit, then add a PID loop to that unit.
My question is, how can I create a PID loop without having an I/O Unit?