| 摘要 |
<p>PURPOSE:To analyze abnormality speedily without evaluating all logical expressions on every sampling operation by evaluating only logical expressions regarding variation of the process signal of a plant selectively. CONSTITUTION:The processing signal obtained from the plant at constant intervals of time is inputted to a signal input device 6. The input signal is supplied to an input signal processor 7 to check whether its value varies or not and the evaluation result is sent to an input signal storage device 8. The input signal storage device 8 and an evaluation order storage device 9 are used to evaluate the logical expressions regarding the input signal which has the variation. The last evaluation result is substituted in other logical ex pressions as it is. Consequently, the output signal which contains abnormality diagnostic logic generated previously by an abnormality diagnostic logic storage device 10 is inputted to an abnormality diagnostic processor 11, whose diagnostic result is displayed on a diagnostic result display device 12 to an operator.</p> |
