| 摘要 |
PURPOSE:To attain the loop reconstitution of a switching loop from present use into spare, by installing plrual monitors on a loop, and monitoring the status of the monitor of the present use system by the monitor of the spare system. CONSTITUTION:If a failure occurs in a present use monitor 51, and arrives in a spare monitor 52, under the sate that bits of supervisor status are not controlled the monitor 52 releases the spare mode of the device itself and transmits the switching command of the reception line to exchanges 53-55 by using a transmission line 57 of the spare system. To the monitor 51, one bit of the supervisor status is used as the through-mode. After a prescribed time, when communication is executed by using the line 57, the monitor 52 plays the major role and trasmits a frame. In this case, the supervisor status is neglected. |
