Article number 90060

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


  • Access of older door phone systems with up to 2 bell buttons to an analogue port of a modern PBX 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
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The conversion of telephony to IP often involves purchasing a new PBX. Although modern PBX systems are state-of-the-art and offer all sorts of modern features, but you will not find a connection for the existing door phones anywhere? Auerswald has 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 PBX. The existing door terminal, from Siedle, Ritto, Grothe or Auerswald for example, can be kept.


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


Features & technical data

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Technical Highlights
Dimensions Height (mm) 81 / Width (mm) 142 / Depth (mm) 27
Casing material plastic
Weight (g) 136
Door bell button, potential-free Max. 2, potential-free
Light relay (direct current) Voltage minimum 12 / Voltage (maximum) 40
Light relay (alternating current) Voltage minimum 8 / Voltage (maximum) 12
Door opener relay (direct current) Voltage minimum 12 / Voltage (maximum) 40
Door opener relay (alternating current) Voltage minimum 8 / Voltage (maximum) 12
Door intercom connection, 4-wire system as per FTZ 123 D12-0 (direct current) Voltage minimum 9 / Voltage (maximum) 12
Delivery scope
  • Door phone adapter TSA-a/b
  • Setup guide
  • Mounting material

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