Hello.

I have one problem with plasma misfire. The problem is that plasma HT65 sometimes won't start. I have mounted THC controll with UP, Down and ARC OK signals as inputs. Is there any chance to write a macro to turn off (M5) and then turn on (M3) plasma again when it comes to misfire? Is somebody here to help me write this?

Greetings
Nino
SLO

You could write a custom macro (say M101 for Torch on, M102 for Torch off) which is your "firing routine" macro. It would include probing the plate, lifting to pierce height, firing the torch, waiting for ARC OK, pierce height delay, then lowering to cut height and cutting. You could just write a simple timeout function, that if you don't get ARC OK, the torch will touch off and try to fire again.

Then, you just need to modify your post processor (from SheetCAM or whatever you're using) to use your macros M101, and M102.

Also, I would check the quality of your work clamp connection (grind the plate clean) and how rusty the pierce location is. Clean plate makes a really big difference for me to avoid misfires.