| 摘要 |
PURPOSE:To attain loss-of-carrier-disconnection by providing a disconnection controller which outputs a transmission stop signal to a modulation/demodulation part and which outputs a timer start signal to a timer, the timer which outputs a disconnection signal and a switch which operates by means of the input of the disconnection signal and which disconnects connection between an exchange line and the modulation/demodulation part. CONSTITUTION:The disconnection controller 13 receives a call abandonment request from outside and outputs to the modulation/demodulation part 10 the stop signal stopping the transmission of a modulated wave. Said unit 13 simultaneously outputs the timer start signal starting the timer. Consequently, the modulation/demodulation part 10 receives the stop signal and directly stops transmitting the modulated wave. On the other hand, the timer 12 counts for a prescribed time, and outputs the disconnection signal to the switch 11. However, time which the timer counts is set to be that in which a MODEM in an opposite station can sufficiently detect a state without the demodulated wave from this side. The switch 11 receives the disconnection signal and can directly abandon the line.
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