The following is a copy of my email to Tormach who replied they had not seen this before and could not reproduce it. I am posting this here and on the Tormach forum for any comments.
******
I experienced a fault while manually stepping both X and Z axes simultaneously but don’t know if it is a bug in the controller or if I was doing the wrong thing. The fault occurred a few times but with slightly different behaviour.
The first time was after I had held down the keyboard arrow key to slowly move the X axis in positive direction while stepping the Z axis lower using the shuttle jog. After I released the keys, all motion stopped but when I subsequently attempted to slow jog the Z axis, it would move only in the up direction whether I used the shuttle or the keyboard. Manual movement of the other axes was normal. I Reset the machine but Z axis still would only move up when slow jogging (I did not try fast jogging). I powered off the machine and computer and restarted. Individual manual movement of all three axes was normal. I ran a short program without an error.
I again tried to induce the error by repeating the keystroking and this time I noted the sequence of first releasing the X arrow key and then the shuttle inner ring. After release, the X axis kept moving in the same direction. I was able to stop the movement by holding down the X arrow for about 5 secs then releasing it. The X axis stopped but the Z axis then stepped down about 0.5mm and stopped. I repeated the same keystroking but the subsequent behaviour was normal. I tried a few more times varying the key release sequence but all behaviour was normal.
I once again powered off and on but could not induce the problem. I have since machined parts without a problem
This was the first time I have held an arrow key down while shuttling. Is this misuse or a bug?
*********
Bevin