| 摘要 |
PURPOSE:To realize simulatenous calls and an individual call, by providing a control signal generating means having a caller equipment designating signal with different length corresponding to the output signals of a mark signal and a caller equipment designating means. CONSTITUTION:A switched line 1 and an extension 2 are connected to a transmission/reception circuit 4 via a line closing means 3. A control signal reception circuit 5 receives the control signal of a call signal incoming from the extension 2, etc., and a control signal transmission circuit 7 sends the control signal of the call signal, etc., to the extension 2. A control means 13 is constituted with a microcomputer, and provided with a timepiece means 13a which measures the interval of the pulse of a received control signal, a timer means 13b which gets the interval of the pulse of the control signal to be transmitted, and a timer means 13c which times out in 60 seconds. An individual call signal consists of the mark signal with prescribed width and an identification signal properly time-delayed from the mark signal. In such way, it is possible to perform the simultaneous calls and the individual call.
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