Welcome to LQ!
Here is something I like, and you may too.
Open a terminal window and
tail -f /var/log/syslog
Leave the window open and insert your USB device.
As you insert it it will generate system messages and the tail -f
command will show them to you in real-time.
This is good for all hot-plug devices (USB, PCMCIA)
to see what messages they generate.
(And though linux sometimes refer to "COM1", "COM2" etc., those are really
DOS/Windows names for the serial ports. As linux devices, they are
usually called /dev/ttyS0, /dev/ttyS1 etc.)