Sennheiser WiCOS - Manual (Page 45)

43
Running a conference
̈
Press the selection key A 8 or the selection key B 9 to trigger circuits
via a home controller.
Depending on the setting, pressing key
8 or 9 transmits a start signal
or a stop signal. As long as you keep the key 8 or 9 pressed, the LED
next to the key lights up.
9 8
C CV D DV