| 摘要 |
PURPOSE:To prevent an operation of a process from being stopped due to noise, by leading a counter function into an abnormality detecting operation of a process controller, and comparing an abnormality count value in a prescribed period and a value which has been set in advance, at every control period. CONSTITUTION:A process controller 6 inputs a process data from a detecting end 8 through a signal converter 7, executes a detecting operation of a process abnormality through an input data checking part 2, and outputs a manipulated variable to an operating end 9 from the signal converter 7 through an arithmetic part 3, an output processing part 4, and an output checking part 5. In this case, a counting means is provided, and when the number of samples CU of an input abnormality which is detected in a prescribed period, against a set number CT of an operator is CU>=CT, it is decided that the process is abnormal, and at the time of CU<CT, a value of CU is disregarded and it is decided that no abnormality is generated in the process. In this regard, the count value CU is reset at every prescribed period. |
