Something is hijacking the MO USB COM port

lutorm · Post by **lutorm** » Fri Mar 16, 2007 1:15 pm

Hey all,
A new issue just started appearing for me using my MX212. Currently, something is hijacking the USB COM port when the computer boots. LCDC says it can't open communications, and something is sending a repeating character sequence consisting of "<spc><weird char><spc><spc>" to the display every 5-10 seconds. I can see it appearing after bootup. If I unplug the display USB cable, wait 30s and plug it back in, LCDC can use it.

The only thing I've done recently that I can imagine would affect this is to switch my UPS from a serial port one to a USB one (APC BackUPS ES 500). Is it possible that whatever daemon looks for the UPS also hijacks the display and thinks it's another UPS? I don't know how to figure out which program has opened the port, is that possible? Any other ideas?

Thanks,

/Patrik

Post by **Ray** » Sat Mar 17, 2007 10:50 pm

Give Portmon a go, it can tell you which process is writing to the serial port.

lutorm · Post by **lutorm** » Tue Mar 20, 2007 1:57 am

Thanks for the tip. Figured it out first, though. It was ups.exe that was doing it, disabling that service made the problem go away (and interestingly enough had no effect on the ups monitoring which still works fine....)

Post by **Henry** » Tue Mar 20, 2007 11:24 pm

Now that I would not expect... but glad it got sorted out.