| 摘要 |
PURPOSE:To inhibit the transfer of a call when the called subscriber is absent and to prevent an ineffective calling action, by using a remote control signal transmitted to a trunk line to stop the detection of an incoming signal to the trunk line. CONSTITUTION:When a bell signal arrives at an originating trunk line R2, this signal is detected by an incoming signal detecting circuit 5. Then a relay contact rl3 is turned on by a control circuit 9. Then a specificremote control signal outputted to the line R2 from a telephone at the receiver side is detected by a remote control signal detecting circuit 6. The circuit 9 receives the output from the circuit 6, and this output is latched by a latch circuit 25 with generation of an output. This latch output is inverted, and an NAND gate 23 is closed. Therefore the bell signals supplied to an incoming signal circuit R1 and the gate 23 are not accepted and neither is transferred. |
