Need Help!- Spindle index switch and G540

[cmanning]

I have a few questions that I hope someone can answer about a new setup I'm working on. I'm using a G540 and Mach3 Turn to drive a lathe. I am moving from an optical sensor with a multi-notch plate to a Hall effect sensor for my spindle indexing (Mach3 is no longer supporting the multi-notch timing method.)

I found this thread on building the sensor. The output is connected to Pos4 on the G540. When the sensor is inactive, I measure 8V between Pos4 and PSU ground at Pos12. When the sensor is active I measure 0V. The G540 doesn't seem to be passing this along to Mach3 (in Ports and Pins Input, Index is setup as Port#1 Pin 13, Active High.)

I suspect that the output I'm sending to the G540 is the problem. Any ideas on what I need to change to get this working? What exactly is the G540 looking for as an input? I'd like to use the same switch arrangements for limit switches at some point, so getting this working would be great.

Thanks
Chris

[grizzlymog]

Your sensor is measuring 0V when it is active? If this is the case, your pin 13 should be configured as active low...no?