Adapter for connecting 4-wire or FTZ door phones to an analogue port of modern ICT systems

Access of older door phone systems with up to 2 bell buttons to an analogue port of a modern ICT system

Inverter from 4-wire and FTZ 123 D 12-0 interface to analogue subscriber ports

Additional switching options via optional a/b Switching Modules

Power supply via bell transformer

Separate volume control for both speech channels, impedance adjustable

Your advantages in detail

The conversion of telephony to IP often involves purchasing a new ICT system. Although these modern systems are state-of-the-art and offer all sorts of modern features, you will not find a connection for the existing door phones anywhere. Here's the solution:

With the TSA-a/b door phone adapter, door terminals with an older 4-core interface or a 2-core connection in accordance with FTZ 123 D 12-0, which perhaps cannot be easily replaced for structural reasons, can be connected to the analogue port of a modern, VoIP-enabled ICT system. The existing door terminal, from Siedle, Ritto, Grothe or Auerswald/FONtevo for example, can be kept.

The TSA-a/b is suitable for use on all conventional ICT systems with analogue subscriber ports.

Features & technical data

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Power supply

bell transformer, 8 V – 12 V AC or 12 V – 40 V DC, 0,5 A max.

System connection

analogue subscriber port of an ICT system

Door phone connection

4 wire system or FTZ 123 D 12-0 interface (e.g. Siedle, Ritto, Grothe), power supply 9 V / 12 V DC, 200 mA (can be selected)

Bell button

2 max., dry contact

Door opening relais

8 V – 12 V AC, 12 V – 40 V DC, 2 A

Light relaiy

8 V – 12 V AC, 12 V – 40 V DC, 1 A

Casing material

plastic, grey

Dimensions (w x h x d)

142 mm x 81 mm x 27 mm


136 g



Delivery Scope

  • Door phone adapter TSA-a/b
  • Mounting material
  • Setup guide

Top Sellers

Sales Configurator (SC)

- the easy way to the right system

Customer requirements for communication solutions are constantly increasing and with them the complexity and scalability of ITC systems. Project planning therefore takes up more and more time. Here, the free Sales Configurator offers a simple and fast solution. It gives you the opportunity to efficiently plan communication solutions and create project planning proposals.

Sales Configurator (SC)