RSheets (Customer) asked a question.
PID will not loop/control (Productivity 2000)
My PID will not control, it goes to a value of output and stays there, no matter the PV, the output is based on what it saw when it was enabled. If i manual turn the loop on/off/on or toggle from auto to manual and back, it picks up a new output. but otherwise it wont control. it locks into whatever value it saw at the beginning. Its like the controller or the PID is not looping. I followed Garry's you tube example,. checked all of his values, ran an auto tune, and still nothing. This particular controller has 4 PID loops, and none of them seem to be working. Any idea on what i am doing wrong? I can post pictures if that would help or a file.
I completely rebuilt the Logic, and it works now, i am still unsure what was going on, i need to integrate the hmi now, i will update again if it continues. It still acts weird and needs to be initialized multiple times.
Where the tags in the PID used some place else in the program. The last write wins and it may have been over wrote.
+1 z28z34man
https://accautomation.ca/productivity-1000-series-plc-pid-instruction/
Here is the post that goes with the YouTube video.
Regards,
Garry
@z28z34man (Customer)
I was using the PID terms in all of my loops as they control basically the same system duplicated 3 times. The limits and ranges were also being shared.
I was NOT sharing SV/PV or output.
I have gone to three separate loops, no sharing, and it is working so far, I will update if I have any other issues. I am sure you are both right on this, i was just trying to save on the amount of data I had to enter.