Door speakerphone
A door hands-free system ( TFE ) is an intercom of an electrical intercom system that is located outside the garden gate, building, apartment or office .
The door intercom can be part of a dedicated door intercom system or integrated into a telephone system. The designation as a hands-free device refers to the fact that there is no handset at the door intercom . The TFE enables the visitor to be identified and his request to be clarified without opening the door immediately.
Analogous to the peephole , TFEs with built-in cameras are becoming more and more popular.
Integration in telephone systems
A doorbell / door call is signaled like a telephone call on the telephone sets of the telephone system, the door is opened by dialing a code.
Diversion to an external subscriber line, such as a mobile phone , is possible. It is called a pharmacist connection , as this variant is often used for pharmacies on call.
The connection to telephone systems can be made using
- Adapter between the interface of the TFE and the telephone system (if necessary with transformer / power supply and amplifier)
- TFE with an interface compatible with the telephone system
TFE telephone system interfaces
- ab interface for operation like an analog telephone as an extension of a telephone system without a special connection
- Also CE 2-wire interface Telekom 2-wire called
- FTZ-123-D-12 interface
- IP-based using 10 / 100BASE-T Ethernet for operation like a SIP telephone using VoIP on the corresponding telephone systems
literature
- Werner Bärwald: Expert practice lexicon communication technologies . Networks - Services - Applications, Expert Verlag, Renningen 2009, ISBN 978-3-8169-2843-0
- Hubert Zitt: ISDN and DSL . Markt + Technik Verlag, Munich 2004, ISBN 3-8272-6630-0
