PID Control Labview 7.1.1

[AirSea]

Hello, I have successfully created a PWM controller for my application and built a simple proportional controller into creating my pulse width output.  This got rid of the basic "drifting" problem of my device output but now a new problem concerning steady state error has arisen where the output is offset from my set point.  To combat this problem, I have heard that I should also implement integral control into my algorithm.  Looking through the daqmx examples, it appears to me that all the example PID vi's contain only P controllers when I looked at them more closely.  For traditional daq, I found a complete P, I, and D controller and was hoping to find something similar for daqmx.  Does anybody know of any example vi's online or if I am not looking at the packaged examples correctly?  Any help would be appreciated.  Also of note is that my setpoint is also changing slightly in real time.  I don't know if this has significance for more advanced controllers, but I thought I should mention it.

Thanks,
Nick

[Arun_V]

Hello Nick,

You can pretty much take the simple PID.vi from the traditional DAQ example and plug it in place of the P controller in the DAQmx examples. If you do the PID toolkit for LabVIEW, then it has a set of PID VIs that you could use.

I am sure you know PID, but I have included a link on PID below.

https://www.ni.com/en/shop/labview/pid-theory-explained.html

Also, please take a look at the 'NI Ready-to-Run Controls Starter Kit' which has executables and VIs for PID applications with our DAQ boards.

Thanks,

Arun V

National Instruments