Air pressure monitoring

My VMC uses pneumatics for the ATC.
Obviously tool change won't work if air supply is missing or pressure too low, but also if heavy tools are loaded the carousel may fall down if air supply is not present.

An air pressure switch is present. The old control wen't immediately to alarm state if pressure were too low.

Any ideas on the best way to configure this in linuxcnc?
I want any moves to stop and also stop spindle if pressure is lost.
I could add it as a condition for emergency stop, but I would like to have resume as easy as possible.

Machine off - How easy/hard is it to resume program run?
Pause - spindle doesn't stop? (I want this to avoid the spindle running unneccesary for long time in case I am running unattended and the pressure is lost)

motion.feed-inhibit and motion.spindle-inhibit are meant for this sort of thing.
www.linuxcnc.org/docs/2.7/html/config/co...html#sec:motion-pins

available from linuxcnc 2.6 +

set them false movement will stop and spindle will stop, set them true and spindle will start and motion will start.
You may want to delay motion starting again till the spindle has time to resume.

Chris M