thanks for digging out this information. I had seen references to reverse engineering the protocol, but didn't track them down far enough to see the part about the MPG encoding only supporting 21 discrete values. This seems pretty crazy. Perhaps if the sampling rate is high enough this might be enough, but it sure seems odd. I've pretty much resigned myself to not having MPG capabilities. That's what comes when with an inexpensive device whose manufacturer is essentially impossible to reach. Same goes for my controller card (AKZ250). The card actually supports a direct wired MPG. If I decide I want it bad enough, I 'll guess I'll have to wire one directly to the controller board. I did find a US outfit that sells the pendant and this controller card. They claimed it worked, but when I probed farther there were questions. They promised to go to their lab to test it out, but never called me back. I took that as confirmation they couldn't get it to work.
Apparently Mach3 does support MPG over USB, but the implementation for this controller and/or my card are inadequate to the task.