Hypersensing with THCAD - better way to do ohmic sensing

I cloned ohmic.comp and made an ohmic_dev.comp with a few changes.

Mainly, moving the arc_on calculation before the ohmic_on logic, and then using the arc_on signal to tell us whether we should turn the ohmic signal on; still looking at the voltage to determine on/off.

While cutting, the arc_on signal ensures that ohmic_on is never set, so no interruptions due to nozzle shorting material while cutting. However, THC should prevent that anyway!

With my dry run (plasma cutter off) testing, it allows the ohmic_on signal to interrupt (pause) during typical cut motion. However, when the arc_on pin is true due to cutting voltages this will not matter.

The problem is that even though ohmic_on is true while jogging && arc_on is false, plasmac does not check for ohmic state outside of probing and cutting states. The torch jogs (with ohmicsense.ohmic-on TRUE), and then when it's finished its jog THEN it throws the ohmic triggered error because it has changed state to PROBE and we haven't reached the probe Z height yet. This would require plasmac to add ohmic sensing during typical jogging, preferably toggleable with a checkbox if the user wants this feature or not.

Hope this is clear. Can make a video if you need...

Thanks for saving me some work. I wonder if you could unlinkp motion.probe−input and connect the ohmicsense pin to it instead?
That would take plasmac out of the picture.

It still needs some more testing. I tried it with the plasma on and it would trigger during the pierce, causing an interruption. I think it's because ohmic_on goes low when moving to pierce height bc contact is no longer made and arc is off, and then when the arc initiates it ramps ohmic_volts back up to arc voltage, but goes above threshold and below full scale thcad volts before it gets there. It needs to be state aware, or just monitor torch-on signal

I had similar issues in the past and I anded the probe signal with a digital input (M67/M68) so I had control from Gcode

I've been monitoring the plasmac.state-out pin. During jog moves between cuts it is at state 0 (idle). The other one I watched was plasmac:motion-type, which had a output of 1 during a jog. Either of these could be used, but how can we invoke an interrupt (pause) condition for plasmac? Is there a global pause hook we could tap?

Yes, I'd like it to mimic the situation where ohmic probe triggered outside of probe state. Raises Z to safe height.

Thanks, I'll give these a shot, could work just as well. My magnetic breakaway has about 2-3 degrees of alignment error due to no locating features other than matching pairs of magnets. A collision may not be enough to break the torch away, but enough to knock it off square. An ohmic trigger would prevent it