[Alan Anderson]

In LabVIEW, you need to place two functions in the Begin.vi block diagram. Use a Compressor Open to define which Spike relay is controlling the compressor and which digital input is connected to the pressure switch. Wire the RefNum output from the Open function to the RefNum input of a Compressor Start function.

That's all you need to do in order to make it work. To be complete, you should also wire the RefNum from the Start function to a Compressor RefNum Set function and give it a useful name like "Compressor". Then, in the Finish.vi block diagram, use a Compressor RefNum Get to retrieve the RefNum and wire it to a Compressor Close function, following the pattern shown for the Motor Drive RefNum.


I think one of the provided LabVIEW examples shows how to do this.