I’ve set up things according to these instructions, where ttyXRUSB2 is mentioned. Also, on the Multitech Conduit there’s a symbolic link from /dev/gps0 to /dev/ttyXRUSB2. So I suppose the path should be right. I tried to run the tests you suggested, but they don’t seem to work:
admin@mtcdt:~$ sudo cat < /dev/ttyXRUSB0
-bash: /dev/ttyXRUSB0: Permission denied
admin@mtcdt:~$ sudo cat < /dev/ttyXRUSB1
-bash: /dev/ttyXRUSB1: Permission denied
admin@mtcdt:~$ sudo cat < /dev/ttyXRUSB2
-bash: /dev/ttyXRUSB2: Permission denied
admin@mtcdt:~$ sudo cat < /dev/ttyXRUSB3
-bash: /dev/ttyXRUSB3: Permission denied
admin@mtcdt:~$
The packet forwarder has been stopped before executing the tests, an I tried both with started and stopped gpsd.
Speaking of gpsd - it is enabled by default. Is it needed for the packet forwarder supporting TDOA timestamps or does it interfere with it?