Mach3 not controlling THC?

Hi guys,

I have a legacy Crossfire machine with my own added THC system using a CNC4PC THC-1 controller. I have all the inputs set up in Mach.

When using test mode on the THC-1, turning the knob, I can see on the diagnostics page in Mach torch up, torch down, and torch on lighting up respectively. The problem is that the torch never moves up or down on the z axis.

I have “Allow THC UP/DOWN Control even if not in THC mode” checked, no change.

One thing I didn’t set is under “Spindle Setup”, and Relay control output. I’ve seen a few other people use that setting, but I have no idea what it’s for. I don’t have a relay that controls my THC so I never set anything in there.

Anyone experienced this before? I am using the RnRMotionController if that makes any difference.