A switching arrangement for telephone exchange systems in which a telephone subscriber station includes telephone and data devices, a telephone exchange installation includes an exchange network having a telephone exchange line leading to the subscriber station, and a separate data exchange system has a separate data exchange line for connection with a selected data exchange subscriber, said switching arrangement comprising:
- (a) special connection means (S-VS) selectable via the exchange network in response to a preassigned special selection signal transmitted to the exchange installation via the telephone exchange line;
- (b) a special facility (ZSE) connected directly with a separate data exchange line (AL-FS) of the separate data exchange system (FS-N);
- (c) said special facility (ZSE) having switching devices (FSG, MOD-ZSE) for receiving and converting line signals and data information destined for said separate data exchange system (FS-N);
- for receiving and converting line signals and data information from the separate data exchange system (FS-N);
- and operable in a data traffic mode for transmitting data information received from the data device of the telephone subscriber station, as converted, to said separate data exchange line;
- and for transmitting data information received from said separate data exchange line, as converted, to the data device of the telephone subscriber station;
- (d) changeover means in said special facility (ZSE) responsive to line signals received as a result of a connection request from one of said telephone subscriber station and said separate data exchange system for switching said special facility (ZSE) from telephone traffic mode to said data traffic mode;
- said changeover means in said data traffic mode providing for said transmission of data information from the data device of the telephone subscriber station along a data transmission path which extends via the telephone exchange line (L), the exchange network, and the special connection means (S-VS) to said special facility (ZSE), and providing for said transmission of data information to the data device of the telephone subscriber station also via said data transmission path;
- (e) said special facility (ZSE) being operable to transmit selection signals via the separate data exchange line (AL-FS) for controlling the separate data exchange system (FS-N) to connect with the desired data exchange subscriber;
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- (f) said special facility (ZSE) being responsive to connection requests which arrive via the separate data exchange line (AL-FS) to process the selection digits received via said separate data exchange line (AL-FS) sufficiently to identify the desired telephone subscriber station (Stat) before release of any supervisory signal to said separate data exchange line (AL-FS).