I have a USB shuttle connected (ShuttleRU - http://cncpendant.ru/en/shuttleru.html). It is recognized sometimes and sometimes it is not in Mach3. I have the "Enable Mach3 USB MPG Mode" checkmarked in the DSPMC configuration window. Rebooting the PC or laptop or Mach3 does not help. I have not found any consistent way to get it to work. I don't know if it is a DSPMC issue or not. Do you have any suggestions on how to debug it?

The DSPMC is loaded with 4.0.41.

For my own notes, I got it to work twice in a row with this sequence; unplug USB pendant, plug in USB pendant, power up DSPMC, boot Mach3.