| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the abnormality of a sensor and to allow the normal operation of a plant by monitoring not only the electrical signal outputted from the sensor but also the correlation state of the measured value. SOLUTION: An electrical signal detected by a sensor 1 is converted into the digital count value by an analog input substrate 4. The value of the sensor 1 is judged by an input count value deviation judging process 20 on whether the electrical signal of the sensor 1 deviates from a normal range or not. If it deviates, an abnormality display is made on a CRT display device 7 by a sensor abnormality reporting process 27 to report an abnormality to an operator 8. The abnormality of the sensor 1 displayed on the CRT display device 7 is formed into an abnormality judgment condition by a sensor abnormality judgment condition generating process 29 and is stored in a sensor abnormality judgment condition file 28. The value of the sensor 1 judged as normal is converted into an engineering unit by a linearizing conversion process 21. The value of a pulse train and the linearized value are compared by a sensor abnormality process 26 in the same unit, then the sensor abnormality can be confirmed by correlation.</p> |
