| 摘要 |
PURPOSE:To reduce a cost by adopting a terminal side transmitting system, and deciding a responsing state in a center side, by only a timing until the inversion and the re-inversion of the polarity of a telephone line in a terminal end. CONSTITUTION:When an automatic communication equipment is started by a prescribed program, the latching relay 22 of an impulse type is operated through a relay control circuit 23 and a telephone line 6 is switched to the side of the automatic communication equipment 7. Subsequently, a center is called by outputting the telephone number of the center from a DP/PB signal outputting circuit 24, and when the polarity detecting circuit 14 of the equipment 7 detects the inversion of the polarity, a data is sent out. When reception of a prescribed data is completed, the center side opens the line 6. In this case, the equipment 7 detects the re-inversion of the polarity by the circuit 14, decides the completion of transmission by an elapsed time from the start of the data transmission, and when it is decided to be uncompleted, the retransmission is executed. Accordingly, by adopting the terminal side transmitting system, the cost can be reduced.
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