Wideye FX 250 User Manual page 15

3.1.3 Primary Handset
The wired Primary Handset has a colour LCD and keypad for making and receiving voice
calls and sending SMS using an interface similar with a mobile phone. It can serve as a
remote access for user to access various BDU functions. The Primary Handset connector
is plugged into the BDU primary handset port and it is powered directly from the BDU.
FX 250 / FX 500 User Manual 13