MC8705 COM Ports and !RESET

Hi All,
We are using the MC8705 Mini card and connecting via USB and the Virtual com ports. We get serial ports for AT Command / CNS / DM and NEMA data. This all works really well, until… Using the AT Command port we canaccess the device as expected but issuing a AT!RESET command which, as expected, resets the device but then we can not access the device back again until it is power cycled.

Interestingly during the reset you can see the Windows Device manager loose the Serial ports and then get them back again, all as expected - BUT neither a Serial port application or AirPrime Watcher can access the device. Pull it out and plug it back in and everything is fine… until you issue another Reset command.

Help !!

Thanks,
Robert

Robert,

What I have found in windows is that if you have a port open i.e. a terminal program when the unit is reset and the port then re enumerates windows holds the port open for some reason making it inaccessible. If you send the reset command and immediately (within a second) close the connection to the com port by either disconnecting it or shutting the terminal down then you may well find it is able to be opened again.

Regards

Matt

Thank you that was exactly the issue :slight_smile:

Of course it means that if the device should reset at anytime then it will be locked out until the port is closed :frowning: Does anyone know a way to prevent this from happening…

Thanks
Robert

Robert,

Unfortunately I have not found a solution to it myself yet.

Regards

Matt

Oh well I’ll keep looking at let you know if I find anything…

Robert