Hi,
Ok you've made some points.
but I would think that needs to be built into the pose processor because most machines use THC
That's what I'm have said before THC is not, nor can it be anything to do with the post. Remember the post produces Gcode....but THC is not driven by Gcode, it's a realtime
voltage control loop, that is a realtime hardware control that if you like 'overrides' the Gcode file.
As for some of the rest:
Basically it needs to turn the plasma torch on and off. Because there is a time delay with the plasma torch coming on, there needs to be a G4 dwell of a couple seconds before any G1 moves.
This is best handled by a macro. Call m101() for instance. Anytime m101() is encountered in the Gcode file the torch will turn on, with the required delay and NOT proceed with any
subsequent Gcode UNTIL the macro is complete.
In Mach3, the Plasma post processor initially moves the torch up .5” before the first cut is made. After a cut is made the torch Is again moved up a half inch as the torch moves to the next cut position.
These too would be perfect candidates for macros, say m102() and m103().
Now you have three macros to control the behaviour of the torch now all you have to do is induce the post to insert in the Gcode file the macro calls at the required time.
There are a number of possibilities. One that I have used for defining a 'Safe location' in four axis toolpaths is called Pass Through. In Fusion/Manufacture/setup/ManualNC you'll find some
useful methods to insert code into a Gcode file, including Pass Through. All of these option can be automated.
I would suggest that you start by defining exactly the steps that you want the machine to take, for example the Torch Start sequence above. Code that sequence as a macro....then insert that macro
into the Gcode either manually or in automated fashion. There is no Gcode instruction to Start the Torch, so a post can't really do that, what it could do is insert a macro, which is just one line,
in this case m101, and you code what you want to happen in that macro.
Craig