On this page you will find specific information about using LabVIEW as a PID controller for a flow control loop with an Equilibar FCV.īelow is a schematic showing how the system is generally set up. Water Hammer and Chatter with Equilibar Back Pressure RegulatorsĮquilibar valves function as back pressure regulators by design and can be set up and used in flow control applications using a flow meter and control logic as explained on our flow control page.įor a review of the various types of control systems you can use to set up an Equilibar FCV for flow control, please visit our “ getting started with flow control ” page.Diaphragm Selection for Equilibar Regulators.Considerations for Oxygen Rich Applications.We tested on the motor before the manually test of the PV. Output = (Kperror) + (Ki integral) + (Kdderivative) We already did it on past years when the programming was on RC (C language), but we decided to try another kind of programming. Here we want to attach a motor on a encoder, set a SP and get the encoder pulses as variable process, but we were intending to do an output curve that starts on maximum(error high) and while the PV increases, the output decreases until a value near 0 (motor stops spinning). 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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