Dear All,
I have an Allen Bradley PID question and appreciate if anyone can advice me here. Basically we have 4 heating profiles in a machine with PID control in the PLC.
We key in the setpoint from the Panel View, then the PID instruction will control the pulse of the heating profile through the relays.
All these 4 profiles had been working well all the while. Recently we tried to tuned the P and I parameter to get better performance. The 4 profiles work well, but suddenly one of the profile went out of control. We are unable to control the PID control variable output.
Please refer to the pictures. Pic 1-1 show the PID that is working normally.
We see can see the PV is close to the SP. And Output % is the right figure to control the output.
Pic 2-1 show the PID that doesn’t work well. The PV is far from the setpoint and the Output % is 100.
I had monitor the Controller Tag for the RTD input channels. All these 4 give me the correct values.
Hope there is anyone who can advice me. Lot of thanks!
I have an Allen Bradley PID question and appreciate if anyone can advice me here. Basically we have 4 heating profiles in a machine with PID control in the PLC.
We key in the setpoint from the Panel View, then the PID instruction will control the pulse of the heating profile through the relays.
All these 4 profiles had been working well all the while. Recently we tried to tuned the P and I parameter to get better performance. The 4 profiles work well, but suddenly one of the profile went out of control. We are unable to control the PID control variable output.
Please refer to the pictures. Pic 1-1 show the PID that is working normally.
We see can see the PV is close to the SP. And Output % is the right figure to control the output.
Pic 2-1 show the PID that doesn’t work well. The PV is far from the setpoint and the Output % is 100.
I had monitor the Controller Tag for the RTD input channels. All these 4 give me the correct values.
Hope there is anyone who can advice me. Lot of thanks!
