AWADo
An automatic changeover switch junction box enables two analog telephones or a telephone and a private additional device of group B to be connected to an analog line . The connection can be made either via the main connection line (HAsl) or on an extension line (NAsl).
Appearance
The AWADo has the appearance of a conventional TAE- F socket (a socket for a TAE-F plug). The only external distinguishing feature is a toggle symbol on the cover. Older versions have the appearance of a junction box . However, they do not have a direct connection option for an end device.
There is both a surface-mounted and a flush-mounted version.
Modes of operation
The AWADo knows two modes of operation:
- AWADo 1 operating mode : Operation for two telephones with equal rights. The phone that seizes the outside line first receives the connection.
- Operating mode AWADo 2 : Operation for two telephones or one telephone and a private additional device of group B (ZGB). The telephone connected to station 1 has priority. As soon as the telephone receiver is picked up on telephone 1 , it receives the connection, even if a connection already exists on intercom 2.
- AWADo 1/3 operating mode : Version for connecting three telephones
- AWADo 1/4 operating mode : Version for connecting four telephones
There are devices in the versions AWADo 1, AWADo 2 and AWADo 1/2. With the AWADo 1/2 version, operating modes 1 or 2 can be switched over using a switch, jumper or similar in the AWADo.
connection
The connection is made via screw terminals inside the AWADo. There are terminals for:
| La | Exchange line (or from the telephone system ) a-wire |
| Lb | Exchange line (or from the telephone system) b-core |
| E. | Telecommunications operating earth (only for telephone systems) |
| a1 | Call station 1 a-wire |
| b1 | Call station 1 b-core |
| W1 | Call station 1 W wire (alarm clock wire) |
| a2 | Call station 2 a-wire |
| b2 | Call station 2 b-core |
| W2 | Call station 2 W-wire |
When using the pulse dialing procedure , the AWADo only works with telephones that have a W wire. This is only available with old Bundespost or Telekom devices. Newer devices no longer have a W wire. When using the multi-frequency dialing method, telephones without a W-wire can also be used; Bridges between a and W are to be used at the respective microphone units.
For the AWADo-2 function, a telephone with disconnection of the W-wire (most telephones with a keypad of the Deutsche Bundespost) when the telephone receiver is picked up at call station 1 is required. Telephones with a number switch ( W48 , FeTAp 61, FeTAp 79) do not switch off the W wire when the telephone receiver is picked up. This is why this operating mode does not work with a telephone without switching off the W wire at call station 1.
A terminal device without a W wire can also be connected to call station 2. Then a wire bridge must be inserted between a2 and W2. This also applies to older AWADos on call station 1 that do not have a TAE-F socket. For AWADos with TAE-F socket, only a telephone with a W wire can be connected to this. Otherwise you have to connect another TAE socket via the screw terminals a1, b1 and W1, insert the jumper there and plug in the telephone 1. The TAE socket in the AWADo must then not be used as the screw terminals a1, b1 and W1 are automatically switched off. Therefore, inserting a wire jumper alone has no effect there (the wire jumper inserted there only serves to correctly release the connection when the connector is removed). This is only recommended for telephones that support multi-frequency dialing .
In the last socket of a TAE series connection that is connected to an AWADo, a wire bridge must always be inserted between a2 and W. If this bridge is missing at the end of the series connection of a branch, the AWADo often blocks if no telephone is connected to the branch concerned or the telephone is unplugged; the other branch can then no longer establish a connection. If the bridge is present, when the telephone is unplugged from the branch concerned, the W- is connected to the a-wire connected to contact a2 and the AWADo is triggered.
With older AWADos, La and Lb must not be interchanged. The order of connections a, b, W on the device side must be strictly adhered to up to the telephone.
In the case of a telephone system, the telecommunications operating earth must be connected through to the telephones.
Further development
Due to the lack of the W wire in modern telephones, the AWADo is no longer produced today. In the 1980s / 1990s, the further development of automatic multiple switches (AMS type 1/2) or T2 switch , which is also available for up to four telephones ( type 1/4 ), was developed. Here the microphone units are only connected with two wires. A priority function as with the AWADo 2 is no longer available here.
literature
- Connection instructions for automatic changeover switch AWADo 1 AP / UP . German Federal Post Office