Pair machine with provide code

[Garito]

Fact:
We can configure a usb to launch a program on the computer
See: http://unix.stackexchange.com/questions/28548/how-to-run-custom-scripts-upon-usb-device-plug-in

Idea:
The program will set an electronic identificator (I haven't seen the doc to know where this is already retrieved but I'm pretty sure it is done) in to the local server
Then any setted provider code will be associated with this particular computer
When it's done (the server could send us a confirmation), the person will unplug it and move to the next

Caveat to research:
What if the port is not working? Have the usb some led to flash? Specific model?
Must we inform we are trying to set a computer to the server? If the tested computer doesn't show up -> inform the person to try another port?