The PCMI counts pump cycles by sensing the presence of the air valve piston(Turbo-Flo)or air valve spool (Pro-Flo). The Sensor, located at the air valve end cap, detects the presence of a magnet located at the end of the air valve piston/spool.
The PCMI unit registers a complete pump cycle when the piston/spool shifts away from the sensor and subsequently returns to the original position. The counter resets itself to zero automatically after reaching 100 million cycles.
The PCMI unit has a reset switch located on the face of the PCMI module that can be activated to allow "on the spot" resetting of the counter or disabled to prevent inadvertent loss of data. The unit also has the ability to be reset from a remote location.