Olav:
> I have trouble entering a GPS tracker (work), which is recognised as a device
> at /dev/ttyACM0; trying to mount it, I get an error: 'ttyACM0 is not a block
> device'.

"ACM" stands for "Abstract Control Model", see page 26
(printed page 15) 3.6.2 Abstract Control Model in
http://cscott.net/usb_dev/data/devclass/usbcdc11.pdf:

With an Abstract Control Model, the USB device understands
standard V.25ter (AT) commands.

I.e. your device acts like a modem, and /dev/ttyACM0 is the serial
device which connects to it (like my old usb posts modem).

Try connecting to it with "cu -l /dev/ttyACM0 -s 4800" or try and
see if xgps finds it. I don't know how the AT commands gets into the
picture, but somehow you should see nmea traffic coming, have a look
at https://en.wikipedia.org/wiki/NMEA_0183.

Regards,
/Karl Hammar

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