You might have a driver problem in linux. Is there anything in the app notes or other doco that says which drivers/kernel modules need to be installed?
Try this:
Log into your linux box
unplug the dev board
type
tail -f /var/log/messages
to tail out the system log (syslog) messages
plug in the dev board
see what is displayed in the log.
The log entry should show you some info about what’s just been plugged into the USB. If the Linux Kernel can find a driver, you’ll see which com port (ttyUSBxxx) your module has been connected to, otherwise you’ll probably get an ‘unrecognised device’ message of some sort, with some debug info to help sort out the problem.
Note: depending on your linux distribution, the syslog messages may not be on /var/log/messages.
If you’re still stuck, post the results of the USB connection here and I’ll have a look at it with you. Unfortunately I don’t have one of these devices myself so I can’t tell you immediately how to set them up.