[sdmuleman]

Got a problem I could use some help with - my computer is loosing the keyboard when Mach 3 is open..... This is new build system I'm putting together on a Boss 3 mill. The PC is a Dell optiplex 755 running Windows XP. I'm running a parallel port BOB and Kelling stepper drivers. The Mach 3 system is operating correctly in all respects from what I can tell - all axis and spindle seem to be operating correctly and there is no sign of freezing/lagging. Both the mouse and keyboard are USB, and both are the generic units that came with the PC. The mouse works consistently and has had no issues, but the keyboard is a different story. Initially I had issues jogging where it would stop working after a bit as if the keyboard was faulty or it had a dirty key, but that issue seems to have gone away. At that time I did try a second similar keyboard I have which didn't solve the problem.

When Mach3 is open, even minimized, the keyboard will stop working and the 'num lock/caps lock/srcoll lock lights' (as applicable) will go out as if it was unplugged after a certain time. Windows does not show any indication of a problem at this time. If the keyboard is unplugged and plugged back in, either to the same or a different USB port, it will recognize it as a new device, install drivers and it will start working again for a bit. (~1-5 min) Notably, when the spindle is started the keyboard immediately stops working, and the plug/replug fix does not work and causes an error. The mouse continues to work properly at all times, and there are no apparent problems with the software except that you can't input anything/jog due to the lack of keyboard. I have tried different keyboards and different USB ports to no avail.

This is the 2nd machine I have built using a nearly identical PC (same PC but different video card and ~3month time difference so possible version differences) and BOB and the first machine didn't have this problem so I am confused.

Thanks,
~John

[kb0nly]

I have been having this problem randomly also, i can go hours though of it working fine then suddenly i go to hit tab and jog with the arrows and no response from Mach3.

[sdmuleman]

Well, after a fair bit of playing with things I've come to the conclusion that this appears to a noise issue, likely due to use of what I suspect is an unshielded parallel port cable. Not sure why noise on the parallel port would cause the USB keyboard to go wonky, but I was able to pretty conclusively pin it down to that cable, and upon consideration I realize that the cable I got is a generic computer parallel cable, vs the cnc4pc shielded cable I had on the previous setup. Hopefully replacing the cable fixes the problem.