New Project with Mesa 7I96 and THCAD-05

deleted, no need for more confusion from my confusion

I saw your one arrow is pointing at the "-2" for the arc voltage.  If this bothers you, you can set a window for which the GUI will display 0 and not fluctuate.  This wont affect normal cutting.  That is explained here:   linuxcnc.org/docs/devel/html/plasma/qtplasmac.html#_zero_window

I checked yesterday that your ohmic sensing offset and scale was set correctly in  your custom.hal

See what happens if you jog the Z axis down until the torch touches the material. It should light up in the GUI

Sorry guys it seems my image was not clear enough. The top arrow with to point at Arc OK and the lower one was for Ohmic sensor indicators. Voltage display not a worry as I did see the expected volts with the 9 volt battery attached. I did have the ohmic box lit when I was trying to get an indication. And it did not show in Hal Show. I am using a micro switch in place of the torch tip and metal surface, switch closed = tip on metal. There is box on the parameters page that is for ohmic offset, that is what I thought needed a value in place of the 00.0 that is in there now.
 

You only need to adjust that if probe testing setup shows the height as incorrect. This is to compensate for any debounce delays etc.

You cant just touch the tip to the metal and expect the Ohmic light to light up the same as it does if you pick up the float switch or pull the breakaway.

To get the ohmic to light up, you would have to touch the tip to the metal AND press OHMIC TEST.  Then it should light up.

Alternatively, it would light up during a PROBE TEST cycle (and maybe you are saying this is where it fails)