THC300 configs question

[jcizek]

I am using the THC300 sample configs for my plasma table and am attempting to modify them enough to use them with CandCNC's LCTHC since it appears the THC300 config uses almost exactly the same inputs and outputs. I have everything working as it should, float switch indicates properly in the PyVCP panel, the up and down inputs from the THC show up properly in the VCP, all the limits work right. The machine home's properly.
The problem comes when I try to turn the torch on, when I do (or when G code attempts to) the Z axis starts heading downwards at an *incredible* rate of speed until it throws a following error and stops. I have increased my FERROR in the ini just for trial purposes, and it doesn't matter how high it is, it sends the Z axis down WAY faster than it's capable of and then errors. I have the Z axis velocity max set to 1.0 (60ipm) in the ini, and it homes at that speed properly, but when turning on the torch, it flys down and errors.

It's a bit hard to totally understand the process since there are NO docs for the THC sample configs, but looking at the flow chart included, I believe what is happening is that to turn the torch on, the machine starts the Z axis down looking for the float switch input, at which time it should reverse Z and raise it to float switch distance + pierce height, THEN fire the torch. But the Z is coming down as some VERY high rate and throwing the FERROR.

I have posted at linuxcnc.org but haven't raised too many ideas over there so thought i'd post here and see if anyone else can help shed some light as I am running out of ideas on what to check next. Thanks very much!
-James

[chester88]

James post on the emc maillist. More developers hang out there then here.
John T ( Big John ) uses torch control on a plasma.
He usually reads here too...

[jcizek]

Thanks for the tip. I am in conversation with John T over on linuxcnc.org right now. We haven't been able to isolate the problem as of yet, but working on it! I just thought I'd post here too to get the most exposure, never know who might have an idea!!

Thanks again for your tip! -James