The reason that we had two pressure sensors last year was to do a "hysteresis". You would turn off the pump when the pressure got to whatever the high sensor was set at (say 115 PSI) and only turn on again when the pressure got below the low sensor (say 100 PSI). This kept the pump from cycling on and off rapidly.
If you read the
Pneumatics Manual from this year, you will see that the provided switch provides hysteresis. All you need to do is something like:
if pump_switch is 1, turn on pump, else turn off pump
This is much easier then last year :-)