Ger here is the spec sheet i got with my machine. I have a db9 connector on the outside of the control box for limit and home switches... the spec shows that the probe is connected to pin 6... how its wired on the inside i have no idea without opening it up... So would I use underr input signals enable probe and port1 pin 6 active low? When I do this as soon as i click the auto tool zero button i get an error saying that its already grounded. If i uncheck the active low. and hit the auto tool zero and /I ground the plate it doesnt stop.... Now when i put pin 15 under the pin number, it doesn't stop either....