Does anyone know what the User Access Pins are used for in the USB-6363 device? What type of signal are they supposed to read and what are they capable of doing?
The USB-6363 BNC device is matching the BNC-2120 terminal interface. The "USER" BNC and screw terminals do not connect to the DAQ device, but only to each other and act as convenient patch spots to bring in external signals.
The BNC-2120 Installation Guide (page 13) has more information.