| 摘要 |
PURPOSE:To reduce a trouble to be occurred under operation, by providing a patrol function in a processing circuit for abnormality and confirming the operation of the abnormality processing circuit under operation of the current system by the patrol function, and preventing the system down due to the trouble of the processing circuit for abnormality. CONSTITUTION:A system consists of plural processing devices 1 and 4 and an input/output device 3, and this system is provided with an abnormality processing circuit 5, and the current processing device 1 and the stand-by processing device 2 are switched by swithes 5-3 and 5-4 of this circuit 5. This circuit 5 is provided with an OR circuit 5-1, to which an abnormality signal S1 of the processing device 1 and a patrol signal S2 are inputted, and a switch controlling circuit 5-2 which branches signals S1 and S2, and the abnormal operation is confirmed during the system operation of the current processing device 1 by the patrol function due to circuits 5-1 and 5-2, and switches 5-3 and 5-4 are switched to prevent the system down due to troubles. |
