QTPlasmaC post processor - SheetCam?

Yes, that was one of the original reasons the ohmic test was included. It was intended to check if there was a short like yours before starting a job. It does not happen very often. I only ever experienced it once and I found a bit of rubbish inside the tip,  much like you did. I have thought of setting it up to use one thcad. I'm sure it could be done fairly easily.

Here is a quick test where I jumped the shield to the nozzle and then feed voltage from my ohmic into it and then ground the nozzle and the voltage drops like a stone. My thcad-10 is using opto22 and relays to isolate everything so that’s why I have to trigger the ohmic button to send voltage to the nozzle.



youtube.com/shorts/fuJnQ76LXl8?si=pr583jeB8bvqNj0g

You could get rid of the short and try adding an isolated 24v power supply (Meanwell hdr-15-24) that is connected to the plasma inputs on the thcad. When cutting, nothing will get damaged. The hypersensing component can see full torch voltage when you are cutting  and it does not care... so this should give you the confidence to do it

You might need to and2 the probe signal so it will only turn on when actually probing.