I am currently retrofitting a large 24ft x 9ft plasma table with mach3. It is equipped with 1hp ac servos for x and y axis and a 350w servo on z axis.

I'm using the smooth stepper interface on x and y axis and that seems to be working fine.

Here is the problem. I used an Eaton plc and operator interface to run the z axis using tip voltage to controll the height. This system works great with one minor hick up. I need a antidive signal from Mach3. Is there a way to configure an extra output from Mach that energizes when the servos are decelerating to freeze the THC?

One extra note this system has a rapid rate of 1000ipm and due to the servo encoder resolution running x and y directly on the parallel port is not an option.

Have never had a plasma but I think there is a plugin for THC, have you looked at that?
Hood