Smart Doorbell Marcel Zuidwijk on KOCH TC50 Doorbell

Hello
I am not getting any further with this project. I bought the Smart Doorbell from Marcel Zuidwijk (Smart Doorbell – Marcel Zuidwijk). I want to operate this in a TC50 from KOCH (Swiss brand).
I now have problems with the wiring. What I have found out so far, that the white and blue cable are under current (low current). When I connected both POWER ports of the Smart Doorbell, I had a connection via ESP in the Home Assistant for a short time.
Can someone point out how I need to wire it? Below pictures and here still links of the TC50:
https://www.kochag.ch/media/Medien/Produkteinformation/PI_TC50_A4_d.pdf
https://www.kochag.ch/media/Medien/Bedienungsanleitung/BA_TC50_A4_d.pdf
https://www.kochag.ch/media/Medien/Schema/SC_Beiblatt_zu_Schemas_TCBus_d.pdf



Did you ever get this working with your Koch tc50?

Just in case anyone is still looking for a TCS solution, here’s something that could be interesting for you:

It’s made for TCS / Koch Intercom Bus Communication but also supports older analogue intercoms.