| 摘要 |
PURPOSE:To prevent a data error and various kinds of alarms due to the switching of an active system or the switching of a subordinate destination clock by making a standby system subordinate to an in-equipment reference pulse generated by the active system. CONSTITUTION:When a system N acts like an active system, a selective circuit 108 selects a signal 101, a selective circuit 109 selects a signal 110, the signal 110 is inputted to a PLO 112 and an internal reference frame signal of the equipment of the system N whose frequency and phase are in matching with those of the signal 101 is generated. Moreover, in this case, a standby system E selects a signal 104 received by the system N, and the frequency and phase of the internal reference frame signal of the equipment of the system E are in matching with those of the signal 101. That is, since the frequency and phase of various clocks of the system E are in matching with those of various clocks of the system N, the occurrence of data error or various kinds of alarms is prevented when the active system is replaced from the system N into the system E. |
