Another Valid Arc Lost Post

I have used both methods, and they do work properly when set correctly, but i still prefer to use the hardware ARCOK, as can be noticed from the builds i do, i add that to most of the plasma cutters, be it with an reed contact or and inductor and some added electronics.
With software there are several issues to deal with to get it right, some plasma cutters will continue to output voltage in the range of 150 to 280V even after the torch is shut off since they have capacitors and that voltage will slowly fall back to 0 so for a split second when the torch is turned of the THC will start moving it down. Never really a big issue as it never reaches the material.
Some, especially inverter ones will have a 160 to 180V on the torch in cases where the pilot arc "missed" to transfer or did not strike an arc, so that will also cause the THC to synthesize the ARCOK signal and start moving torch down to lower the voltage while there is no arc or cutting going on.n Same thing happens on transformer plasma's but the voltage is much higher up to 280V, so the THC will move down rapidly and hit the material.
On my last build using THCAD i have the min arc voltage set to 80V and max at 150V to avoid any of those issues, and it works perfectly, never missed a single start.

phillc54 wrote: Check Arc Fail Timeout in the Config Panel

linuxcnc.org/docs/2.8/html/plasma/plasma...de.html#config-panel

THC Delay works identically for all modes.

EDIT: Set Arc OK High really high until you tune it in.

I missed the edit. Sorry about that. It was pretty late for me. I have the arc ok set as high as I can get it, 300v.

rodw wrote: Just remember that if your plasma cutter decides the arc is lost, its going to cut the arc regardless of any synthesised arcOK signal. NOt using your ArcOK signal is just adding one more potential failure point.

Its possible any relay you've used on your ArcOK circuit could be responsible for most of the latency. I've wired mine direct to a Mesa Input.

You could compensate for latency in ArcOK by reducing pierce dealy.

The arc usually does not establish at all. There have even been times that it doesnt strike at all, just the solenoid actuates to shut the air off and valid arc fail. Which is why I was thinking it might be a timer.

I can wire it directly to an input easily. I basically have no terminals or relays left in the panel anyway. Just to be clear, it isnt wired right now.

I dont think I know more than Hypertherm. Just kinda wanted to try something to improve my issue is all. Maybe it was silly. Itll be easy enough to throw that in there.

Can you still fire the torch manually ?
If yes, fire it and check if you get that error, it seems you have grounding / shielding issues.

So I went ahead and wired up the arc ok but it is acting a little strange. The issue is 100% my fault. But I cant get the software to see my signal. I am wired to pin 30. When checking the hal meter it goes from false to positive when the torch fires. I added "net plasmac: arc-ok-in => hm2_7i76e.0.7i76.0.0.input-30 to my connections hal. The "plasmac: arc-ok-in" signal goes from false to true but I cant get the arc ok light to come on in the software. The mode has also been switched from 0 to 1. Kinda stumped on this one.

[strike]The "plasmac: arc-ok-in" signal should normally be false.
[/strike]
[strike]Seems like you might need to use the in-not to invert the signal[/strike]

EDIT: oops, I misread that.