| 摘要 |
PROBLEM TO BE SOLVED: To detect a fault location up to the unit of a board of a path forming an approach line in an MCA system. SOLUTION: Approach lines between a light controller and a radio base station exist for each radio unit. A monitor controller starts line test and the radio base station side loops the lines (relays form a loop). In this state, a preset path is formed and when an NPU 1 transmits predetermined data, the data are returned via a loop 4 of the approach line 3 at the base station side and received by the NPU 1. As a result of this loop test, when the NPU 1 was able to receive the data as they are that are transmitted by the NPU 1, the test is normally finished and it is discriminated that no fault exists on the line. On the other hand, when the transmission data cannot normally be received, only the path formation is changed and the data are sent/received again without changing the approach line, and when the data cannot be received normally even then, it is discriminated that the approach line has a fault. |
