Normally, we would use a touchoff procedure in a seperate file that was called on pen down
Here is a very old example. Normally, I would touch of in reverse until contact broke for cleaner probing.
o<touchoff> sub
(#1 pierce height, #2 pierce delay, #3 cut height)
F10
G38.2 Z-1.75 (Probe to find the surface)
G91
G1 Z0.070 (Raise up to Z0)
G90
G92 Z0 (Set Z0)
G1 Z#1
M3 S1
M66 P0 L1 Q5 (Wait for Arc OK from Torch)
G4 P#2 (Pause for pierce delay)
F25
Z#3 (goto cut height)
o<touchoff> endsub
M2
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