The FODB is the Fiber Optic distribution interface between the master computer and the FOOSB which is the hardware interface at the mechanism to be controlled and/or status. The unit is a standard 2U rack mount chassis.

The front panel has 48 LED indicators each associated with either a receive FO line or a transmit FO line.
The LED is illuminated when the FO line is active high (illuminated). A push button switch is available that when pressed, illuminates all of the LEDs as a test convenience. The front panel provides a manual override switch for each of the 24 transmit channels. The switch is protected such that an inadvertent operation is avoided. The switch enables a REMOTE mode in the down position, manual OFF in the center position, and manual ON in the up position. The rear panel provides 24 FO drivers, 24 FO receivers, and the interface from the DIO board in the master computer.