2-wire analog system compatibility

Hi there,
I wrote a few times to email support, buth with no response…

I have 2-wire intercom, but it is (I think) analog system 1+N. There are only 2 places for wires, there is no possibility to connect more of them.
It works like that:

  • if someone rings I have a blinking led and ring tone as long as someone is pressing the button outside. If someone press button 3 times I have 3 rings, If someone holds the button I have continuos ringing.
  • if I pick up the handset I can hear and talk and then If I press the button inside, the intercom short-cuts the 2 wires together and this activates the latch in the door. In this time I can’t talk and hear. If I release the button I can hear and talk again.
  • if I put down the handset, I can’t open the door again until someone rings next time
  • generally - if someone rings it is impossible to open the door without taking the handset into hand, if handset is on intercom and I press the button nothing happens

I want to buy OPENER to extend my system, but I would like to know if it will work…

Hi Pawel,
intercom systems that work in this way are supported (e.g. Elcom HAT-402). May I ask you about the brand and model of your intercom?
Best regards

Thank you for your answer.

I live in Poland, this is CYFRAL UNIFON TCL intercom - very popular in our country. But it is out of production now (building is from 2010). Today’s model is CYFRAL UNIFON SLIM.

In my opinion:
SW1 is switch under handset
SW2 is switch downstairs at the building
SW3 is button on my intercom to open the latch

I think, that the main unit in the building is TD3 or TD4, eventually TD6:

All diagrams you can find here:

Looking forward for info from you :slight_smile:
I can help in developing with this type of intercoms, if you have any questions or if I can check something - please let me know.


Any answer from your side?

I though that something has changed in nuki support, at least for new, still developed product… But now I see, that I was wrong and that looks as usually… :unamused:

Hi Pawel,
I am really sorry for the late reply, I was out of office last week. Please give me some time to respond properly to your post. Thanks!
Best regards

Can you tell me, where those to wires connect to your intercom? Are those connection points somehow labeled? Maybe you could send me pictures from the inside of your intercom and where the two wires are connected! Thanks!
Best regards

The wires comes out from the wall and they are soldered directly to PCB at the botom of the intercom (i know, it is not usuall).
The connection points (on schematic above) are in the left top corner of course. LINE1 and GND.
It is photo from the internet, but it looks exactly the same.
And of course SW2 “RINGER” is switch to turn off the ringer of the intercom placed inside it, not the switch downstairs…

Hi Pawel,
does the door open, if you shortcut the two wires on the backside? If yes, this connection scheme should work:

Any outcome? This intercome has been successfully connected?

I haven’t try yet… Opener still in the box, unpacked.