Apparatus for and method of detecting a malfunction of a controller.

摘要

An deviation E between a setting value SV and an actual phase value PV in a controller is integrated, and the resulting integrated value S is compared with a predetermined threshold D for detecting a malfunction. Checking a change in setting value SV, checking an increase or a decrease in deviation E and comparison with the absolute value ¦E x S¦ are made to ensure stability against fluctuations and rapid detection of a malfunction. <IMAGE>