Okay, here's my setup. I have a passive probe from tormach wired into my mach3 (non tormach) machine. One wire to pin 15 as an input and the other to ground. I also have a 220 ohm resistor between the input and 5v (like the second wiring drawing on this page :
http://www.cnc4pc.com/Store/osc/product_info.php?products_id=323)
I enabled the pin in Mach3 for probe and leave the active low unchecked. After this I can go into the diagnostics page and see the probe light come on and off as I press on the stylus. However, if I run any G31 command in the MDI, nothing at all happens. No movement and no DRO reaction.
Next, if I go back to ports and pins and enable Active low for the probe, then in the diagnostics screen the led behaves opposite of what it should (as you would expect). But, if I press and hold on the stylus of my probe and run G31, it starts probing until I let go.
So what gives? It works in reverse (which is incorrect), but now how it's supposed to. What am I missing? Do I need a capacitor or something on the probe wiring? I have had the denounce up to 4000 with no noticeable change. Any ideas??