I do not have a ARC ok on the Mach 3 screen or the Texas Micre 301d when I am running.

I was getting a pierce but no movement. The pierce would last until I shut it off on the Mach screen.  I shut off the THC on the Mach screen and I began cutting again. However, I do not get an ARC OK signal at the THC or the ach screen.

The good news is I am cutting as well as ever..

Texas Micro suggested it is the torch (TD A40). At their suggestion I am going to run the test boards again.

I do have a 2nd issue and will post it separately.  This issue is dealing with my feed speed not changing, on the Mach screen with a new g-code.

Any help will be greatly accepted.

Thanks, Bob 

Put an ohm meter on pins 12 and 14 on your TD automation cable.  That will tell you if it's the plasma.  With a good arc, you should see continuity between pins 12 and 14.