Bang & Olufsen BeoLink User Manual page 25

MASTER LINK
Moreover, option 4 can be used if the link room and the main room are
located in such a way that both rooms will be operated simultaneously.
By setting the link room to option 4, the room can be operated
independently of the main room, because the link room will only accept
information from the terminal if the LINK key has been actuated.
NOTE!
The BeoLink Video cannot be set to option 4!
All link room products and link room kits with Master Link connection,
with the exception of BeoLink Video, can be incorporated into this special
setup.
NOTE!
The Beolab 3500 S/W version must be 1.1 or
higher
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