Auto Bed Leveling/Tramming Sensor Wiring
This is the Wiring diagram I have for my inductive sensor. I have not connected it to the rigidboard yet (Hence the work in progress), but this should set up the right control voltage.
The Inductive sensor runs off of 6-36VDC, so powering it with the 5v from the endstop power is not enough. I'm connecting the +24 and -24 to the constant on FAN connector on the extruder board (Fan2). This will create 24vdc on the signal wire. We need to add a pull down resistor of about 2.1k ohm between the signal wire and V-(GND) to create about 4.5v for the input. This should be sufficient to provide the input to the rigidboard.
I would suggest testing your circuit before connecting any inputs to the rigidboard to prevent blowing the input out.