Please ask again if you need clarifications, and best of luck! PS - It seems you already understand a bit about PID controllers, so what is the purpose of those tests? You guys should follow Greg’s suggestion of trying the PID example VIs - they actually simulate a process and will be a lot more helpful. Manually changing the process variable value isn’t really a way to test anything, as it doesn’t represent anything and isn’t even reproducible. When you reached the desired setpoint, would you like the controller output to go to zero? Of course not, because then the motor would stop spinning. Suppose you were controlling a motor’s speed with a PID loop. You are too attached to this “output must go to zero” mantra. Think about this: the controller has no idea of what’s going on other than, at that particular output, it drove the error to zero. Now we ask: why output doesn’t decrease until 0? What we can make to do it in the better way that is possible? We guess that it has something with the I term and with the reinitialize boolean on PID. When the PV = SP the output starts to be constant but not 0.
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