| 摘要 |
PURPOSE:To provide a paging function without exclusive lines or station number, by outputting a different voltage to a signal line transmitting a channel selection signal, inhibiting the channel selection and operating a paging adaptor. CONSTITUTION:In calling another interphone from an interphone T1, a channel selection pulse is outputted to a line 2 from a control signal input circuit 5. In this case, interphones T2, T3 and a paging adaptor PA input signals and a called interphone is responded. A control circuit 12 of the PA discriminates, signal of 12 volts from that of 5 volts, and neglects the selection signal of 5V. In performing paging from the interphone T1, a paging signal of 12V is transmitted to the line 2 from the circuit 5. |
