| 摘要 |
<p>PURPOSE: To check the continuity of a channel by connecting a transmitter- receiver of a c check personnel for the continuity to the channel when a characteristic of a trunk module is inspection request of continuity and discriminating whether or not a call tone is received within a prescribed time from a channel in an opposite direction after the transmission of the call tone. CONSTITUTION: When a characteristics of a trunk module 10 is inspection request of continuity, a continuity check request is set to a continuity check indication in a head number message and the resulting message is sent, and a call is connected to a continuity check tone transmitter-receiver of a service circuit assignment module 30. For the check time, when a call tone sent via a forward communication channel is received at a proper level within a prescribed time via a communication channel in an opposite direction, it is discriminated that the check is successful. Then the transmission of a check tone is interrupted and the connection of the continuity check tone transmitter-receiver is disconnected to terminate the continuity check. Thus, the channel continuity is checked and the reliability of the system is improved.</p> |
