THC that controls z axis externally

I've got a plasma set up here that uses a THC controller from China, It has an INPUT of Arc Start, Up, Down, Auto. And an OUTPUT of Arc-ok, trying to use plasmac and its wanting to INPUT of Up, Down, Ark-ok. Am I missing something easy to change that out, the THC handles everything with voltage and moving the z axis using a dc motor and external interface.

Pictures?

Plasmac mode 2 is designed for THC's like that
linuxcnc.org/docs/devel/html/plasma/qtplasmac.html#qt_mode

From what I can tell mode 2 only works with up and down being inputs, not outputs, am I mistaken?

I expect your connections on the THC are actually outputs and the translation has been lost a bit. EG. To be connected to INPUTS.
DO you have documentation? what does the supplier say?

Here's the manual that came with it, I will say that when it's powered up I can contact the up and down pins with the ground pin and it will move up and down 

I found the manual. This is designed to control a DC motor not a stepper motor.
Its not really suited for Linuxcnc which controls Z axis position precisely.
Assuming you have the complete chinese table, I would replace the Z axis motor and gear box with a nema 23 stepper motor. If you are really lucky mounting hole positions will have been spotted.

I would then throw out the controller and THC and use a THCAD and 7i92/7i76e and let Linuxcnc manage the whole process. You will get much better results..

I have to agree with Rod, had my fair share of removing those damn things and throwing them.
Good business for me though!

Hmmmm, you think theres anyway to run with what I have for the moment? trying to at get this running asap then can modify later