| 摘要 |
时间从属局具备有同步错误检测部(36)，此同步错误检测部(36)具有：CW同步错误检测用计数器，计数在第一方向传送讯框之传送路的同步修正周期；CCW同步错误检测用计数器，计数在第二方向传送讯框之传送路的同步修正周期；CW同步有效期间计时器(363)，当CW同步错误检测用计数器的计数值达到第一设定值，就进行CW同步讯框接收有效期间的计时；CCW同步有效期间计时器(364)，当CCW同步错误检测用计数器的计数值达到第二设定值，就进行CCW同步讯框接收有效期间的计时；CW系同步错误判定部(365)，判定是否在CW同步讯框接收有效期间内接收到CW同步讯框；以及CCW系同步错误判定部(366)，判定是否在CCW同步讯框接收有效期间内接收到CCW同步讯框。; a CCW synchronization error detection counter for counting the synchronization correction cycle on the transmission path that transmits frames in a second direction; a CW synchronization validity period timer (363) for timing a CW synchronization frame reception validity time when a count value of the CW synchronization error detection counter reaches a first setting value; a CCW synchronization validity period timer (364) for timing a CCW synchronization frame reception validity time when a count value of the CCW synchronization error detection counter reaches a second setting value; a CW system synchronization error determination unit (365) for determining whether a CW synchronization frame is received during the CW synchronization frame reception validity time; and a CCW system synchronization error determination unit (366) for determining whether a CCW synchronization frame is received during the CCW synchronization frame reception validity time. |
