Thanks for your answers.
I am studying the "wiascanr" minidriver sample.
I read the "USB Driver" in "Imaging Devices" from the WDK.
I saw the CreateFile and an example of the DeviceIoControl.
I will make some research on I/O control codes... But it would be great if I
find a guideline for the use of ReadFile/Bulk IN, WriteFile/Bulk OUT in order
to receive or send data to a real device, not the fake device of the sample.