I've had this exact same board work pretty much fine, while with my old laptop, running XP.
It used to lose the USB connection once in a while though, suddenly reporting "ddream device is now connected"
while in the middle of the milling process, causing all steppers to pause for several seconds, going completely out of synch with the code,
breaking my end mills sometimes, as it would then pick up from the current code command (the code still running...), and the tool going any random direction, depending on the code, and how far off it went, while the controller board remained offline...
I've figured it must have been my old laptop, dropping the USB device once in a while, or not keeping up altogether,
so I've just put together a new computer, running Win7, and all on-board ports only USB3 now.
and the things have turned even worse.
It will usually start off fine, the board never loses USB connection with the computer anymore,
but several hundred commands down the road it will randomly lose the connection on the plugin level. It stops running the code
and starts violently stepping any random direction, very small steps though, so it never moves enough to break the tool, but it definitely has lost connection with Mach3 app at this point. No Reset button (the Mach3's one, not hardware) or any emergency stop will stop it.
It will continue stepping blindly around until I actually close the Mach3 app altogether. Then it stops, as the plugin also gets unloaded at that time.
I've tried playing with the buffer size, no difference.
I'm not sure if it's to do with the USB3 port I'm using (now the only available...), Windows 7, or something else.
Still investigating, trying to figure this out.
I don't want to build another computer now, with a parallel port and all that.
I rather drop the Mach3 and move to something else....
jj