JP2656264B

PURPOSE:To surely judge the situation for an operator by displaying the causing event of the abnormality in addition to a first alarm in case the abnormality occurs at a large-scale plant and many alarms are produced. CONSTITUTION:When a plant signal is supplied from a plant 9, an alarm process diagnosing device 1 checks whether an estimated alarm is produced or not for the input plant signal based on the data stored in a knowledge data base 7. If so, the presence or absence of a new alarm is checked. When the 'presence' of a new alarm is confirmed, a first occurrence alarm, the newest and most downstream occurrence alarm, and the most important alarm are decided based on the state signal of a device for estimation of the next alarm. Then the genuine cause is decided every plural causing events for those causes of the first occurrence alarm and the result of this decision is displayed on a CRT.