| 摘要 |
PURPOSE:To improve reliability of operation without duplicating the detection system by a circuit wherein the pulse detection system is of a single system, and the measured data is compared with the estimated data to enable detection of failure wherever the failure may be caused in the detection system. CONSTITUTION:Output pulses from a pulse generator 2 are counted at 3, and the resultant data A is compared with the preset value from a presetter 5 in a decision unit 4, so that coincidence output (c) is issued when both values coincide with each other. On the other hand, output of the counter 3 is stored in a register 11 which issues data B upon receiving a preset signal (a), and the data B is replaced by the data from the counter 3 if there present a gate signal (b). Diviation calculation of ¦A-B¦ is carried out in a deviation calculating circuit 12, and the result is fed to a comparison circuit 13. The circuit 13 performs comparison calculation of the right-hand equation using the deviation of ¦A-B¦, insensitive zone deltaN and an estimated amount N1. If the result does not meet the inequation, output of failure detection is issued. At the completion of calculation, a signal (f) indicating that is fed to the register. The data in the register 11 is updatated by a trigger signal from a trigger oscillator 14. |
