My XL Stops Cutting and Carbide Motion Says Not Connected

I have had this problem with the older Carbide motion that the cutter was not found after running a job then turning the XL off to do a tool change. After powering the XL back up Carbide Motion would not see the XL also I wouldn’t get the little audio chirp when powering up the XL, but it never stopped during a cut. I changed the USB cable connecting the XL to the computer and it seamed to go away. Now that I have upgraded to Carbide Motion 4 the problem has come back in a new way. The XL just stops during a slot cut, the screen gives an error “GRBL Error: Serial Port:Unknown Error” and Not Connected. This after successfully cutting 4 other steps of the same task. I then turned off the XL and ran the file again it would get a little further along in the cut and stop again. Same thing happened 4 times. then on the 5th and final cut out id did it again.


This sounds like EMI. Please see:

If that doesn’t help, let us know at and we’ll do our best to help you puzzle this out.

When you say older, what exactly does that mean? What version is your Carbide Motion controller PCB and what version of the Carbide Motion software you’re running?

You post seems to imply there’s an older CM thing and a new CM thing.

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I purchased my XL on Nov. 2016 so i used the CM that was out then, I recently up graded to Carbide Motion 4 and GRBL 1.1 Update. I have been using Vetric’s VCarve Desktop to generate my GCodes.