Quote Originally Posted by JAZZCNC View Post
I must object because My experience is very wide so therefore Valid and very much relavant to CNC MOTION CONTROL.!! . . . . Which is what we are talking about here.!!
Experience has limitations. You almost seem recognise this when you say 'we are talking MOTION CONTROL not Networking etc.' but in falling over yourself to claim limits to the experience of others, you're forgetting applying it to your own.

It's much derided, but theory is necessary to understand what the limitations of one's experience are; ie., the situations it's useful in, and the claims that that experience allows one to make. It allows one to look at what is going on, rather than be confused by a name. For instance, you can fixate on it being called 'motion control', or you can recognise it being called Ethernet is a pretty big hint - ie., that it's a networking technology for, well, networking things and that it doesn't much care if the device you've plugged in is a desktop running a web browser, a VoIP phone or a motion controller.

Simply put - having used some motion controls doesn't qualify you to say that USB is the problem. For instance, given that USB controls tend to be in the lower end of the market whilst Ethernet motion controls tend to be at least 'serious hobby' - so an alternative conclusion would be that USB motion controls tend to be cheap with performance to match - nothing to do with the cable you used to connect it to your PC.

This difference is important, because if USB is the problem, an ethernet motion controller for side-hobby money is a great deal; if the issue is instead that it's simply unreasonable to expect a decent motion controller to be cheap, then one should be wary of any motion controller for less than serious hobby money.

Quote Originally Posted by JAZZCNC View Post
No more will say on this because as Said it detracts from OP problem.!!
The only reason why I'm even talking about Ethernet is that you brought it up. The only reason I'm still talking about it, is because I'm replying to you.

The majority of my post was, in fact on OP's problem. None of yours was.

To try to get it back on track again, if the USB motion controller is likely to be a problem, could it even be the root of the present issue - as in, something goes wrong (eg., command buffer empties during a run) and the controller goes into e-stop mode? (And that guard switch is sorted?)