sparky101 (Customer) asked a question.
I have a P1-540 PLC im looking to do a washbay pump control using pid 2 pumps going into 1 line, having problems with implementing the pid into ladder logic, or is there a better way of doing it? the vfds are ABB-ACS255, And CM5 hmi.
Glad to see you're using the CM5. The HMI is invaluable for viewing the response and tuning a PID loop. Use a trend graph for trending the PV, CV, SP. Display numeric values for all PID loop data, PV, CV, SP, P, I, D, Bias, etc. Include a switch for hand/off/auto mode, and numeric entry for manual mode output value, P, I, and D values. Include other PLC logic status that might control or modify the PID control.
During startup situations, it is very difficult, or impossible, to try all of this using your laptop. You will need to plan for some passcode protection.
It is also very important to shop-test your control panel before connecting the equipment. The minimum test would be to connect an analog simulator (4-20ma?) to simulate your sensor (flow meter?) and connect a decade box to simulate your load (VFD input). Vary simulator and verify input is scaled correctly. Put into hand mode and verify output matches your manual mode output value. Put into off mode and verify output goes to zero. Put into auto mode and monitor output while varying the input and see if the output makes sense, for example, the output winds down when PV is at SP, etc.
Hope this helps.