JPS57194657A - Detecting system of disconnection signal - Google Patents

Abstract

PURPOSE:To simplify the processing of an exchange device and at the same time to decrease the traffic of a circut for control signal, by transmitting the communication end signal via a circuit for general connection provided between the exchange devices which are used by the subscriber. CONSTITUTION:When a subscriber 101 gives a request for communication to an exchange 103, the device 103 decides the communication circuit connected to an exchange device 104 storing a subscriber 102 from a circuit 105 for general connection and preforms a connection between the circuits 107 and 105. At the same time, the device 103 feeds the information of the circuit 105 to the device 104 via a circuit 106 for control signal and preforms a connection between the circuits 105 and 108. Thereafter, the device 103 opens the connection between the circuits 107 and 105 and at the same time transmits the signal of level ''0'' to the device 104 via the circuit 105 after receiving the communication end signal from the subscriber 101. Based on the signal of level ''0'', the device 104 decides that the call end request of the subscriber 101 is acceptd at the device 103. Thus the device 104 opens the connection between the circuits 108 and 105.