Proma sd issues

Afternoon, not sure this is the right section but here it is.
I hope someone has had this issue and has a fix for it. I have seen on youtube linux cnc running with a Proma sd torch height control so I know it can be done.

I was given some plasma table parts, motors, computer etc. I built a table and got it all going. My friend that gave me the parts bought us two Proma SD torch height controllers. Now I am stuck.

The boards in the box are all Probotix I am using Linuxcnc (obviously!) and Sheetcam tng. There is very little about the SD version of Proma THC to be found anywhere.

So here is what I have found while trying to make it go.

With no power to the thc the signal should run straight through and the table should run as normal. However the x and y are fine the z will not move.
Now power up the thc (12v battery for clean power) The thc blinks and flashes as advertised, the z axis starts down and will not stop until I unplug the driver computer. The z axis motor is also very noisy and growly.
I pulled the wires back out of the thc and twisted Dir in/out together and Step in/out together the table runs fine, nice and quiet all three axis.
Leaving Step tied together I separated Dir and tested for polarity (I only have an analogue circuit tester) The wire I have labeled as dir out (I am using the names from the thc so this wire goes to the motor controller) This wire had 5 volts even though emc is not trying to cut. When I trigger emc to follow it's pattern the voltage goes between the 5 volts and no volts as the z axis is activated, stopped and reversed.
There is no negative deflection.

I wired the Dirs back together and separated the Step wires, Using the voltmeter I got approximately 4.75 which drops to approx 4.3 when z is activated. The z axis did not move when I had the voltmeter in line.

Any thoughts?