I have an AVID CNC machine (Mach4 + ESS) and I have added a Drewtronics probe and hopefully today will get a tool setter connected. I have what I think is a basic question about how these 2 will interact.

I know I will use the probe to set work coordinates and most importantly (in the tool setter context) Z height. When I touch off my tool is it seeting an offset from Z 0 of the workpiece or do I need to do tool touch off on the probe?