| 摘要 |
PURPOSE:To attain detection of an abnormality of a transmission line as well as estimation of the abnormal area by arranging in 1:1 transmission controllers NCP on different loop circuits and using a bidirectional loop circuit to have connection between the NCPs of each pair. CONSTITUTION:NCP 01-0n and 11-1n having the same number of detecting functions for abnormal area on the transmission line are arranged on two loop circuit L0 and L1 which perform transmission in direction opposite to each other. Loop link circuits 21-2n connect two NCPs belonging to different circuits L0 and L1 to perform the bidirectional transmission. Terminal link circuits 31 and 32 connect a test terminal 30 to an NCP to perform the bidirectional transmission. Then the terminal 30 gives a command to the NCP 01 and 11 for detection and test of the abnormal area of the transmission line through circuits 31 and 32. At the same time, the terminal 30 can receive the test results from the NCP 01 and 11. |
