U-verse fiber router re. USB

The router includes a USB connector which allows a USB hard drive to be connected and recognized as a NAT drive. When I connect my drive nothing happens. The drive spins on power-up but the router does not indicate a USB connection and the device is not visible in any network search. The router's utility does not mention USB either.

Question: 1. How to activate the USB port?  2. Where can I get a manual for this device?