Did I fry my thc?

I hesitate to even ask about anything that’s not a mesa thcad, but I’m going to anyway.
Im trying to get an arc ok signal from a hypertherm thc to a mesa 7i97t.
The thc uses a 25 pin d connector. Arc ok(motion according to the thc manual) uses pin 17 + and pin 4 -.
I originally connected pin17+ to my power supply common and pin4- to tb4 pin4 on the 7197t. Tb4 pin6 is connected to v24+ on the power supply. 
After a lot of unsuccessful testing, I realized I mixed up my positive and negative.
So I swapped pin17 and pin4, but that didn’t help.
I also tried throwing a relay in, but that didn’t help either.
Now I’m wondering if it’s possible I damaged something with my incorrect wiring.
I know you guys probably aren’t familiar with the thc, so I attached what I think is the relevant part of the manual.
It a hypertherm sensor phc. I’m planning on hitting up hypertherm tomorrow to see what they say.
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From their diagram it looks like the output is switching on the negative side.
If the 7i97 is expecting a positive input, this will not work. I don't know the card but I am sure PCW will guide you.
A relay may be required to send +24v to the input. example bottom right.

I just tried what I think is the top right example without any impact.
I put a jumper between pin 17(thc)and pin 25(thc field +12v) on the thc connection.
then I ran pin 4 (thc) to tb4 pin12(7i97t).
and pin 20(thc field common) to tb4 pin 11.

Is there an easy trick to get arc ok signals without having the arc going?
It was hooked up to a hypertherm hsd 130, but I hooked up a thermal dynamics a60 just to make sure the plasma was actually sending the signal.

Rod,
If I don’t get this figured out soon, I may pick up the z axis you recommended in the other thread. Do you have a link?
Also thanks for sending the corner hold, I haven’t had a chance to look at it, but I appreciate it. 

Im broke and over budget so I’d like to get what I have working, but who knows if that’ll happen.

Alternatively, maybe I can just reuse the z axis I have with a thcad and something like a mesa 7i30 since the z motor is an h bridge. But I’m not even sure what an h bridge is.
This thing is turning into a can of worms.
 

The 7I97 input will work with either input polarity
You should not be able to damage the THC output
as long as you do not wire it directly to power.

The 7I97 input will only put a ~4 ma load on a 24V signal
so as long as the wiring includes the 7I97 input pin pair
in series, there should be no way to damage the THCs
optocoupler outputs.
 

Awesome. Those optocouplers are pretty cool, especially if you’re bad at wiring.
Thanks for the quick responses.
At least I know i didn’t break it, even if it doesn’t work.

I think I may give up on the hypertherm thc.
I went ahead and ordered a thcad but I gotta figure out the z axis. 
I have the hypertherm dc h bridge z axis or was offered a stepper powered z axis from a candcnc setup.
I have a mesa 7i97t, but I’m not sure if I can control either of these z axis’s with it, since it has analog outputs for servos.
I assume getting the stepper axis going would be easier than the h bridge, but I’m often wrong.
Or maybe I should just buy one.
I also know I’ll need a driver. I have an old gecko 540 I could potentially use, but maybe a single axis driver would be better suited. One that’ll work with 7i97t’s analog signals? Or maybe an h bridge driver makes sense?
What do you guys think? 

What are the voltage and current ratings of the existing DC motor on the Z axis?

  24v    2.6amp

If you remove the motor are there any spot drilled holes to mount a NEMA 23 motor?
The one I had had spot drilled holes for a stepper
If not, can you remove the top plate its mounted to and locate on the hole for the shaft so you can drill and tap stepper  mounting holes?

I believe there aren’t any limit switches. It uses stall force and ohmic sensing. I wouldn’t have a problem physically adding limit switches.Im not sure what the encoder looking thing on top of the motor is.Looks like there's brushes.Theres a chip and there’s a wire coming off that that goes to the nut? area for the ball screw.​​​​​​