Also, there are 3 different operation modes.
Manual, simple up and down buttons on the screen.
Digital, which takes an up or down signal from a TCH unit (like the proma).
Analog, which reads the actual voltage from a register. This can be used with any device that can tell Mach4 what the current actual voltage is using a register. So if your motion device has an analog input you can use to get the actual voltage from the plasma unit and can pass that value to a register you're good. Some use a simple PLC for this (like the click from Automation Direct).
The screen doesn't care what device you use. And the THC module doesn't even care if you use our default screen. Everything is controlled through registers. You can run THC using any screen. The values don't have the been shown in the screen anywhere. You can just enter values directly into the registers if you want. Design your own screen and if you want to display the register value, just link the screen element to that register. It's very flexible and as Steve said, should work for most.