2N Home intercom 2N Helios - Secondary switch with dep.button funcion, 1977 v1 - Příručka (Stránka 3)

Example 2 – dep. switch operation for unlimited time:
Dep. switch closure is set to SWITCH 1, dep. switch opening to SWITCH 2.
The dep. switch will close when it has received the password for SWITCH 1
and will remain closed until the communicator has received the password for
SWITCH 2 and until the switching time of SWITCH 2 elapses (parameter
823, it is recommended to set this parameter as low as possible, which is
1s).
Example 3 – dep. switch closure for the duration of the call:
Closure and opening is set to SPEAK. The dep. switch will close when the
line is picked up and open when the line is hung up. For the duration of the
call the dep. switch will be closed.
External button switch
Examples on how to connect network in case of one power supply: