Vertical Communications and FXT - Manual (Page 93)

DSS/BLF Console Operation
The IB64X, IB48X, and IB24X DSS/BLF consoles have additional buttons and
status lights that extend the memory button capability of an adjacent companion
telephone. The buttons can be programmed for automatic dialing (speed dial) or
direct station selection (DSS) with busy lamp field (BLF) using the instructions
provided previously in this guide.
When the installer assigns a DSS/BLF console to a station port, the system
recognizes it as such and automatically clears (blanks) the console buttons so that
you can store numbers at the buttons as you need them.
Large Screen Display Speakerphone Station User’s Guide 85
GCA70-349 Other Advanced Features
IB64X
DSS/BLF Console