Some of pid output value drops to zero In Ext2 SetPoint Mode
we observed sometimes the output of the PID value becomes zero after enabling the external set point mode 2
Type of Block used: ControllerPID(PCDL Library)
Set Point used Parameter in PID:SP2_R
PCDL version:PCDL 5.8-0
800xA verstion: 5.1 RevD FP4
Observation:- 1.There is no change in set point value coming from APC
2. After couple of hours ruing loops in APC mode the problem will appears in some of the loops(Not in All Loops)
Well there are plenty of circumstances where this would happen quite normally and correctly.
What EXACTLY is wrong with the PID output going to zero ? Is there a constant error that makes the Integral action wind the output down ? Does it ramp to zero ? Does it happen immediately when you go to Ext2 mode ? What are the tuning values ? How is the loop configured ? What are your output ramp rates ? Is the loop being forced into some other override mode like Tracking ?