| 摘要 |
PURPOSE:To form a loop-back in a simple and assured way, by forming the 2nd loop-back in case a test signal is not sent back from the next node and then forming the 3rd loop-back if the test signal transmitted from the preceding node is not received. CONSTITUTION:It is decided that a fault arises between a node 10 and the next node in case no test signal is sent back from the node following the node 10. Thus a loop-back 2 is formed at a node 10', then it is decided that a fault arises between a node 10'' and the preceding node if no test signal is received at the node 10'' from the preceding node. Then a loop-back 3 is formed. |
