BUS TROUBLE DETECTION SYSTEM OF BUS LOOP SYSTEM

摘要

PURPOSE:To detect a trouble occurring position by switching control from an act system bus to which trouble occurs to a stand-by bus system and then sending data in specific pattern to the trouble system bus. CONSTITUTION:If the trouble occurs between (x) and (y) on the bus system 0, bus controllers BC1 and BC2 once receiving a signal A from a central bus controller CBU, return an answer signal B to the controller CBU by using a 1- system bus. The controller CBU when receiving the signal B sends a trouble detection start signal C to the controllers BC1 and BC2 and also sends a detection signal D to a 0-system output side, and the detection signal D is supervised on the input system of the system 0 for a time T. The controller BC1 and BC2 once recognizing the signal C sends the signals D to respective output sides of the system 0 and the signal D is supervised on the input side of the system 0 for a time T. Then, the controllers BC1 and BC2 recognize the signal D of the 0-system bus and reset a timer T. In this case, the signal D of the controller BC2 is not recognized within the time T because of the trouble between (x) and (y). That is reported to the controller CBU through the 1-system bus and the controller CBU recognizes the trouble between (x) and (y) on the 0-system bus.