| 摘要 |
<p>PURPOSE:To easily grasp the occurrence place of an emergency state and to deal with it speedily by displaying the identification code of a calling emergency telephone set to a receiving operator. CONSTITUTION:A control circuit when receiving a control code sent from an individual discriminator 5 transmits the identification code of the emergency telephone set to the individual discriminator 5, and then performs control so that the emergency telephone set is connected to a circuit and made ready for a talk. An exchange 4 which detects a DC loop from this code transmitter, on the other hand, sends a call signal to the individual discriminator 5. The individual discriminator 5 when detecting the call signal forms a DC loop to the exchange. Then, a control code indicating the start of transmission is sent to the code transmitter and when an identification code is received from the code transmitter, it is displayed out on a display device to let a person in charge of telephone set for reception know that. When the telephone set 1 for reception enters an off-hook state, a DC loop is formed and the telephone set 1 for reception is connected to the circuit and made ready for a talk.</p> |
