Pressure Switch Wiring

I am not sure how to wire in the pressure switch for the pneumatics. The switch has two terminals the PWM digital has three. Do I use just the ground and positive?

Thank You

You should connect the black wire to the C terminal, and the white wire to the NC terminal. The red wire is not used for hooking up switches.

EDIT: There is more info on page 9 of this document:

Wire switches between the desired digital input signal pin and a ground pin.