Automatic monitor system for transmitted answer

Abstract

Abstract PURPOSE:To prevent a long-time holding of the automatic call control unit and then increase the transmission efficiency not by performing the answer discrimination for the terminal unit of the called subscriber via the automatic call control unit but by performing at the side of the data device and via the answer signal of the terminal unit at the called subscriber side. CONSTITUTION:Switchboard control circuit 7 consists of incoming detecting relay 11, CML (connected MODEM set to line) relay 12, circuit protecting circuit 13, level converting 14 and others. On the other hand, automatic call control circuit 8 comprises originating/incoming collision preventing relay 15, dial pulse sending circuit 16, originating control circuit 18, EON (end code) detecting circuit 26 and others. When circuit 26 detects end code EON sent from the data device, end signal DSC is immediately sent to the data device via circuit 14 in circuit 7. Receiving the end signal, the data device gives release to start signal CRQ and then to circuit 8 each. On the other hand, the answer signal is sent from the called subscriber's terminal unit, and the data device detects the answer signal. In such way, the answer sent from the called subscriber's terminal is discriminated to then start immediately the transmission of the data.

Inventors

• 👤 Toyokazu Ishizaki

Bibliographic Details