Definitiion of a plc

[chrisbramall 1]

We use the ABB Commander 350 series controller to act as a small PLC for duty standby pumping stations. The unit uses logic statements and maths statements which are configuarable as well as the more traditional PID routines. We have also used the Eurotherm T640 which has a simalar setup. So what are they PLC's or PID's

[godfrey 0]

I would call them a PLC. You program them. They store and execute logic. They have inputs and outputs. They react to inputs. They control things. PIDs are a subset of PLCs.