Very interesting stuff, so without an arcok system, a straight M03-M05 should be so fast as to not give any action at all? Probably just make a relay quiver somewhere.
Ok, so we switch on, wait for arcok, then switch off, is that the correct internal sequence?
Inside Mach there is a loop following the M03 that waits to see an arcok signal BEFORE processing the next command which in my case is M05, but I guess could just as easily be a move etc?
If that is so, then yes there is a long loop involved in getting that signal, in my THC it's created from a Hall effect trigger on the plasma ground lead so the current has to build to trigger point before it's sent, and as you said there are gas valves, relays, even the blowback start cartridge in the torch.
This all explains why a zero pierce delay is never really zero I guess.
Thanks for all this by the way, it's much appreciated.