| 摘要 |
PURPOSE:To obtain a device which detects surely the abmorlality of the operation of the control system, by comparing the output signal as a control signal from a data processing device with the signal due to the normal operation. CONSTITUTION:An abnormality detection signal is generate in accordance with the result of the comparison between a signal corresponding to the frequency of the control signal from a data processing device, which controls the system, and a reference signal corresponding to the frequency of the control signal for the normal operation. For example, an output signal Q0 as a control signal is inputted from a data processing device CPU 11 to an external device 12 through a driver 13, and this signal is transmitted to an abnormality detecting circuit 14. A pulse signal Q1 synchronized with the rise of the output signal Q0 is outputted by a one shot circuit 15, and a pulse signal Q2 synchronized with the fall of the output signal Q0 is outputted by a one shot circuit 16. Output signals Q3 and Q4 are outputted by comparators 19 and 20, and output signals Q5-Q7 are transmitted through a gate circuit and FFs 21-24, thus detecting the abnormality of the operation of the system. |
