FB 250+ Installation Manual
Page 10 of 33
1.3 Below Deck Unit
The BDU is the heart unit of the FBB UE. It has several interface ports and handles all communication
links between the ADU, primary handset and the local communication devices such as analog
telephone, computer, network equipment, navigation equipment etc.
The BDU is supplied by +12V or +24V DC power supply and it supplies a step-up voltage of 40V ~ 43V
DC to the ADU via a single RF / coaxial antenna cable.
1.4 Wired Primary Handset with Cradle
The wired Primary Handset has a colour liquid crystal display (LCD) and keypad for making
and receiving normal voice calls and sending SMS, which both are similar as any mobile
phone. The handset is provided with a cradle.
Additionally, it can serve as a remote access for an user to access various configuration
supported by the BDU.
The Primary Handset’s connector is plugged into the BDU’s primary handset port. It is
powered directly from the BDU.
