Programming a compressor

[plnyyanks]

Originally Posted by ww2freak8

it looks like we are getting up to 7 volts off the spike relay

That doesn't sound right. You should be getting +12, -12, or 0. Check the input wiring - it should go a terminal on the PDB protected by a 20 amp breaker.

Originally Posted by ww2freak8

and the little light on it is orange

If it's solid orange, that means it's outputting neutral (zero volts). If it's trying to get your compressor to run, it'll turn green (forward). There should be a PWM wire between the spike and Relay port 3 on your digital sidecar (like you specified in code)

Originally Posted by ww2freak8

didnt know the pressure switch says anything

When the pressure going through the pressure switch is <120 psi, there will be an open circuit between the two wires coming off it (which should go to DIO 14, like you specified in code). That circuit will close when the pressure reaches 120 psi. This tells the cRIO to turn off the compressor.

Take a look at the Signal Wiring Diagram and the Power Wiring Diagram to see how to wire the pressure switch and a spike relay.