| 摘要 |
PURPOSE:To prevent the high and dry state from being released erroneously, by setting the period from release of the cut-off state of the subscribers circuit to the next scanning of the corresponding subscriber line, to the subscriber scanning period or less, when the cur-off state of the subscriber's circuit is released. CONSTITUTION:When instruction decoder part ODRDEC receives release instruction of the cut-off state, the FF and the TMF are set by the signal from timing circuit part TIMING. Subscriber scanning counter part LSCNCNT generates scanning line driving information. Collating circuit part MATCH collates subscriber position information of information receiving part PSWINF with scanning line driving information, and if they coincide with each other, this circuit part MATCH transmits the output. This output and the AND output of circuit part TMF instruct the release of the cut-off state of subscriber's circuit LC. Since the cut-off contact is released just after the subscriber scanning device completes scanning, the next scanning result becomes normal. |
