How to use the USB port.
The USB port is a Micro B USB connector - a lead for connecting this to a standard A type USB, as used on USB hubs, is available in the StaRFIshrail store. The port uses a FT234X chip from FTDI, and acts as a serial port between the Hub and the computer. The original FTDI PID and VID are retained, but the name of the port (such as is seen on the on the Windows Devices and Printers screen), will appear as StaRFIshrail.
Although data from the readers can be sent out on USB, the main reasons for the USB is for programming and commands (and also for debug). The MERG FCU program will not work on the USB port, you will need to connect via Ethernet for this utility program to work.
When first plugged in, your computer should be on-line, and then it should find the drivers for the FTDI chip automatically.
To use the USB port, you will need a terminal program. I use Mttty for Windows, which is available for free. With this program, you can send files, both programming and commands, and see the returned data in the window.