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Is there a good excel program somewhere or basic breakdown of how to implement a control loop in excel if trying to simulate the performance of a circuit? I have data from an operating plant and am trying to simulate the control loop but I'm not getting the correct outputs for the loop inputs.

Update: I think what i'm missing is basic. I have cv, mv, and sp and I'm trying to simulate the controller. I have the PID settings for the controller as well (I think it was Siemens). Gain is 0.8, Integral time is 15 seconds and i have data on a 2 second sample time (I realize this is low resolution). The issue i'm having is i'm looking at output between t1 and t2 and trying to pull the appropriate data to estimate the PID output but i am consistently getting a different delta and i think I'm just setting it up wrong mathematically.

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  • $\begingroup$ Without any detail, you can use if() statements: =if(a1=7,"do this", "do that") $\endgroup$
    – Solar Mike
    Jul 25 '19 at 10:12
  • $\begingroup$ The Solver may be another possibility you could investigate. $\endgroup$
    – Solar Mike
    Jul 25 '19 at 10:21
  • $\begingroup$ Hi guys. I think what i'm missing is more basic. I have cv, mv, and sp and I'm trying to simulate the controller. I have the PID settings for the controller as well (I think it was Siemens). Gain is 0.8, Integral time is 15 seconds and i have data on a 2 second sample time (I realize this is low resolution). The issue i'm having is i'm looking at output between t1 and t2 and trying to pull the appropriate data to estimate the PID output but i am consistently getting a different delta and i think I'm just setting it up wrong mathematically $\endgroup$
    – user21260
    Jul 25 '19 at 10:27
  • $\begingroup$ You should consider updating your question with the info you have in your comment. $\endgroup$
    – Solar Mike
    Jul 25 '19 at 10:28
  • $\begingroup$ I've done what you're describing, and had it work correctly. Without seeing what you're actually doing, and what PID you're trying to simulate, there's really no way to know where the problem might be. A few suggestions though: You need to know the exact equation that the controller uses, you need to correctly account for the accumulating integral value as time goes by, and you need to know about any limits the controller imposes, such as anti-reset wrap-up, or limits in how much or how fast the output can change in each time step. Are you confident that you've correctly addressed those? $\endgroup$
    – Mark
    Jul 27 '19 at 5:29

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