Quote Originally Posted by JAZZCNC View Post
Don't know if you are using USB version or not but I'd check your PC settings because could be energy saving shutting down the USB ports when thinks Pc is idle.? This would have the same affect as E-stop to the controller because lost connection with PC which would explain why still get E-stop message when not connected.!

Could even be a program working in the background which try's to check ports etc causing blip just long enough to trick controller it's lost connection.
I thought about that also but he said that UCCNC detects a hardware e-Stop, not that it lost connection.