| 摘要 |
PURPOSE:To switch an in-use and spare network concentrated controllers in a simple way and with no dissidence in synchronization, by receiving the control a t each processor within a data exchange to use newly the network concentrated controller at the spare side as the controller at the using side in case each processor of the data exchange receives no question message from the network concentrated controller of the using side in the fixed number of times. CONSTITUTION:When a network concentrated controller 100 of the using side has a fault, no question message is sent to all processors. A using/spare switching device 250 defines newly a network concentrated controller 110 as the controller of the using side in case the device 250 receives no question diagnosis message from the using side in a fixed frequency and accepts only the message from the spare side in a fixed frequency via a question message line 310. This information is supplied also to the controller 110 via a question diagnosis answer line 311. The same switch is carried out to all data exchange processors at a time. Then the in-use/spare switch is performed for all network concentrated controllers. |
