Hi,
This is a quite old analogue intercom with 4 wires:
1 - Audio
2 - GND
3 - +12V (out)
4 - Video
For opening you have to wake up the intercom with one of the followings:
- Door bell (Shourtcut between Audio - GND)
- Press Video Button
- Pick up the handheld speaker
If the intercom is active, you can initiate the opening which is a shortcut between Audio and +12V
Is there an existing supported device which works similarly, or do somebody have any suggestion for wiring?
Thanks