Hi,
I don't have a direct fault line from there as it is simple as A+ B+ 5V+ and a negative that are fed from the encoder
That is from the encoder to the G320, you are interested in the lines between the G320 and your BoB/Mach.
I don't have the G320 manual in front of me but usually there is step, direction and enable lines
FROM your BoB/Mach to the G320 and one line FROM the G320 back TO your BoB/Mach to signal
a servo fault.
You may not have a servo fault signal setup but if thats the case then it cant be a servo fault thats making
Mach Estop, more likely noise on a limit switch say.
There are three common conditions that the G320 would recognise as a fault and signal it so:
1) Overcurrent, if you attempt to accelerate quickly, more than the G320 can handle or you progammed,
2) Overvoltage, usually happens if you try to de-accelerate to fast, the servo acts as a generator and will push
voltage back into the drive, at a high enough level the drive will fault or worse blow,
3) Following error, if the servo lags behind its commanded position beyond a limit that you set it will determine
that the accuracy of the machining job is at risk and fault.
Your Fluke scope should be isolated and so you could put a current shunt in the servo circuit to measure current.
Craig