Why are there three different ground pins on the D-sub connector of my PVM-4210?
Pin 2 is the logic ground for the various enable pins (if you use them).
Pin 7 is the ground for the +24 V power supply.
Pin 12 is the ground connection for the shield braid (shielded cable should be used to connect your gate pulse generator to the pulser).
All three of these ground pins are connected to the same ground internally and are at the same potential as the chassis.