This configuration is to show how to connect the Mesa THCAD card with LinuxCNC on a Plasma Cutter.
There are two configurations, the plasma-5i20 that requires you to have a Mesa 5i20 installed
and the plasma-demo using parallel port. The plasma-demo version is just to show how
this config looks and is not a good candidate for the THCAD card due to the slow update speed
when using a software encoder with the parallel port.

The subroutine touchoff.ngc is used with a floating head and the probe input to set the torch
to the inital height of the cut. The example files x-trim.ngc and touchtest.ngc demonstrate 
the use of touchoff.ngc. The usage of touchoff.ngc requires you to have the probe input and 
and Arc Ok input. It uses M66 to wait for the Arc Ok input after lighting off the torch. Three
parameters are passed to touchoff pierce height, pierce delay, and cut height. In actual use 
you will need to adjust the height to raise the torch after touch off to Z0 to match your 
actual setup.
