| 摘要 |
<p>PURPOSE:To execute a self-diagnosis as to whether an instantaneous generation of an abnormality in a CPU itself exists or not, by providing a storage means for storing a reset signal which is outputted when a program run signals is abnormal, and an alarm means for alarming an abnormality of the CPU, based on a result of storage of the storage means. CONSTITUTION:An output terminal of a runaway monitoring circuit 22 is connected to a set terminal S of a flip-flop 23, and a timer 24 for outputting a reset signal of an H level for a prescribed time after a power source has been turned on its connected to a reset terminal R of the flip-flop 23. An output of the flip-flop 23 is inputted to a microcomputer 21, and when the output of the flip-flop 23 is an H level, it is decided by the CPU 12 that the CPU 12 is abnormal. Also, at the time of displaying whether an abnormality of a sensor, etc., and an actuator, etc., exists or not, and a result of self-diagnosis, by an on-operation of a self-diagnostic switch 31, and an indicator 32, respectively, generation of an abnormality in the CPU 12 is displayed together. In this way, an instantaneous generation of an abnormality in the CPU 12 can be brought to a self-diagnosis.</p> |
