| 摘要 |
PURPOSE:To prevent the trouble of the network of a looped network system wherein transmission lines is doubled, by providing a slave monitoring node in addition to a master monitoring node and allowing the slave monitoring node to function as a substitute for the master monitor node when the master monitoring node is faulty. CONSTITUTION:The master monitoring node MS6 monitors all nodes to find abnormality and performs necessary loop-back control, etc. The slave monitoring node SS7 monitors the master monitoring node MS6 all the time and if the master monitoring node MS6 gets out of order, the loop-back control to a terminal station node TN1 adjacent to the master monitoring node 6 is performed to disconnect the master monitoring station 6 from the loop, so that the slave monitoring station 7 operates as a substitute for the master station 6. |
