[SOLVED] EMC stops functioning but GUI continue

One possibility is a ground loop in the encoder wiring. If you have a case ground or shield from the encoder, it should only connect at the 7I33 end _unless_ the encoder case is electrically isolated from the motor frame, otherwise you will may conduct PWM noise from the motor frame back to the PCs ground, causing all sorts of troubles. For the same reason the encoder ground (V-) should not connect to the encoder shell.

A easy way to check this is to unplug the encoder and make sure all encoder wires measure open to the motor frame
with DVM on high Ohms range

Good guess peter. As it turns out, the culprit (found by exploratoy surgery) was a lost ground in the servo itself. It never occurred to me that the wiring inside of the servo could be messed, but it was. The machine seems to run great on both axis now for about a 4 minutes before they suddenly stop moving and the virtual tool continues, much like the issue before. back to ground zero? i'm not sure.....any thoughts?

Mystery SOLVED. I think...at least for now. I'm able to run the machine for 15 minutes with repeatable results and absolutely no shudder. What did i do?

Well, after thinking about what could possibly cause all this mess, I decided to get funky with my experimentation. The end result was a 5/8" plate of alluminum between the servo dynamics amps and the Mesa board cluster. that seemed to destroy any interference and EMC is being well behaved and predictable. yay.

now on to limit switches et al....

thanks guys,
A