September 25, 2022 at 4:01 pm #120essentialzParticipant
I took a loop I had previously tuned manually for a cooling tower fan, it is pretty dialed in already. I just wanted to see if I would get a different result using your tool. I’m not entirely sure that I have set up the data correctly. I didn’t find where I can set the setpoint I am trying to achieve. is this information not needed for the model?
To my surprise, the values I received are very different from the values I have set. Currently my loop has a proportional constant of 22.5, and an integral time of 5.63 hours. The tool gave me a proportional constant of 0.1020771129517562, with an integral time of 9.39960877111678 seconds
Am I doing something wrong?
Also, have you considered offering an API service? It would be pretty nice if I could send a POST request from my front end and get a response with the tuning values.
September 25, 2022 at 4:16 pm #122essentialzParticipant
- This topic was modified 4 months ago by essentialz.
UPDATE: Ok I read the pdf:
I see that I did not record the required data. I am sorry for the post. I thought you just needed the input x output of the running loop. I now see that you need to go through the step changes in input and record how the loop responds.
A question, if the operating range is from 75 deg F to 85 deg F, do I need to step through all 10 deg F in 1 deg increments to get a reliable sample? In this case not such a big issue, but if the operating range was larger, that would take a long time.September 26, 2022 at 10:28 am #123pidtunerKeymaster
Glad to hear the PDF solved some of your questions.
Regarding the size of the increments, it should be large enough, such that the output signal can be clearly distinguishable from noise.
In other words, the size of the increments should be large enough such that the output signal displays a clear curve that the pidtuner tool can identify, but not too large so you avoid damaging your hardware.
As a rule of thumb, I always try to split my operating range in 3 to 5 levels.
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