Hood
The option you told me about windows controlling the energy of usb is not set.
It worked for a while, then it fails sistematically showing the message "External movement is disconnected". I reset the card disconnecting the usb cable, so, when I reconnect it seems to work, but in about 3 seconds the message comes again. Even the keyboard (usb) fails retarding the response to show the letters typed. It makes me think is something related to the usb port. The computer is a cheap Lenovo but it is new. It has 4 usb ports, 2 for keyborard and mouse, the third is used with the usb-cnc card, the fourth is empty, I calibrated the two axis, then did some movements with G codes for both axis, but since the last fail I can't make it work. The other hint is that the jog function doesn't work. In fact, the fail began when I tryed to move the system with arrow keys. Could it be a tunning fail? (Do the velocity and acceleration of motor tunning affects the movement of programmed feedrate or only the jogging movements?) I'm separating other cables from the usb cable to limit induction. Maybe I have to put a mass connected conductive protection to this cable.
The other option is that the breakboard be failing but Why it has worked alternating with fails?.
This last card interact with another circuit card for Z control. I will contrast to know if it could be origin of fails, although it seems not to be the cause.
Thank you for your help.
Luis J.