Question about using a PLC PID through ethernet?

Would using a PLC PID to control a motor of a loss in weight device where the motor is controlled through a Modbus or ethernet connection be a good application? The weighing scale would also be communicating to the PLC PID via a Modbus or ethernet connection. I believe that controlling through this type of connection would be slower than analog 4-20ma but would it work effectively at all?

Hi Ivan

A standalone PID controller have a update rate at 100 mSec. I don't think speed is a problem.
Do you do the loss in weight calculation in the PLC or do have a "fixed" device?.

Banker

What type of PLC are you intending of using?

Is this ethernet network going to be solely dedicated to the control of the instrumentation?

Any delay in the Process Variable being read into the PLC or Control Variable reaching destination will add lag to the system. What this means is the control variable will not have the calculated effect on the Process Variable.

Hope this helps