Avid CNC Slaved Proximity Sensor for Ganrty Auto Squaring

Hoping someone here can help. Avid CNC is no help, their support sucks!

I have a 4x4 machine using their plug and play NEMA 23 electronics. When I purchased It I only got 3 switches for homing. Now I have purchased a sensor to add to the slaved Y axis for auto squaring of the gantry, but I can't figure out how to set it up in Mach 4. When I have the switch plugged into the slaved input the light comes on when metal is touched to it, but nothing lights up on the 'Diagnostic' tab on Mach 4. Although the diagnostics tab for the ESS does show that it's getting a signal. Just don't know what I need to do to get it working.

Thanks!

There support is very good.
Is each switch wired to a separate input or are they combined or parallel?
What controller are you using to wire them? Can’t remember what electronics they use.
I have mine auto squaring in Mach4 but I have each switch on a separate input.
Much simpler control logic to program this way.