I am trying to get spindle speed to appear in the S True DRO in Mach3. For a sensor I am using an inductive proximity sensor which I think is type NPN (although I am not sure what that means). With the controller I am using, the signal for this sensor goes into a Gecko board and then to pin 13 on the parallel port. In Mach3, Pins and Ports, Input Signals, I have enabled Index, port #1, pin 13, and checked off active low. Turning on the spindle and handholding the sensor I get no reading in Mach3, but the light is flashing at the base of the sensor indicating it is active. The only thing I can think of is that no signal is getting through from the sensor but I am not sure how I would check this.
Of course it could be something different all togeather.
All suggestions, pointers and ideas appreciated.