PidCC control module
I have a question regarding the PidCC control module in 800xA v5.1 rev. D (Control Builder AC800M).
So, in some part of process sequence, I want this PidCC module to start decreasing OUT value to 0.0 (InterractionPar.Faceplate.OutManMode) in manual mode with ramp limits defined by: InterractionPar.Pid.Aux.EnableOutRampMan and InterractionPar.Pid.Aux.OutDecLim. The issue is that when I give the OUT value reference by manually tiping 0.0 in the faceplate, the OUT decreases with defined ramp limits (1%/s). But, when the program executes command InterractionPar.Faceplate.OutManMode := 0.0; the OUT value decreases immediately to 0.0 without ramping.
Does anybody know how to resolve this?
Voted best answer
I'm not quite sure about PidCC logic, but depends on what you described, you can do the following:
- give InterractionPar.Faceplate.OutManMode := 0.0
- together with this use SEL function and pass the output of PidCC trough function Velocitylimiterreal (only when you need OutManMode, othervise use directly PidCC output).
With velocitylimiter function you can fix the ramp of decrease or increase of analog value
Hope this will help, that is just a first idea
i have the same problem
if you use the interaction window of the pid, you could change the output and you can check the correct ramping output (if active) but if you connect with faceplate the tag outmanvalue this operation is not correct
stefan´s answer is correct that you should use the block velocity incremental for solve this