DUPLICATE HIGHWAY SYSTEM CHANGEOVER SYSTEM

摘要

PURPOSE:To eliminate the need for a highway management device managing highways centralizingly by giving an output to both highways at all times and applying independent selection changeover depending on the result of fault detection of each device as to from which system a data is to be read. CONSTITUTION:Output buffers 11 of each device 1 are both ready by the control of an output control section 13. Thus, an output data of the device 1 is simultaneously written in both highways 4,5 and a same data is always given to the 0 system highway 4 and the 1 system highway 5. The data to the device 11 is entered from one highway of them by an input changeover section 12 according to the control of an input control section 15. When a fault detection section 14 detects a fault of the 0 system highway 4, the input control section 15 gives a command to select a data input source to the input changeover section 12 into the 1 system highway 5 thereby selecting the input source to the 1 system highway 5. The input changeover as above is implemented independently for each device 1.