Plant control system and interlock factor specifying method
AssigneesKabushiki Kaisha Toshiba, Toshiba Mitsubishi-Electric Industrial Systems Corporation
InventorsHajime Taruishi, Akira Nojima
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Abstract
This disclosure describes, for a example, a plant control system comprising: program editing means for creating a control program including an interlock condition and diagnosis of interlock; plant control means for executing a program object in the control program; and interlock diagnosing means for updating and displaying satisfaction/dissatisfaction of the interlock condition at a predetermined point before the present, further specifying only a source factor variable of the dissatisfaction even if plural stages of interlock circuits are formed, and automatically displaying the source factor variable in a graphic language, the interlock diagnosing means having a logical operation unit and a display unit.
Claims5
A plant control system comprising:
- program editing means for creating a control program including an interlock condition and diagnosis of an interlock;
- plant control means for executing a program object in the control program;
- a display unit;
- interlock diagnosing means for updating and automatically displaying on the display unit satisfaction/dissatisfaction of the interlock condition in a ladder circuit at a predetermined point in time before the present;
- and
- wherein the interlock diagnosing means specifies a contact that is a first trigger of the dissatisfaction of the interlock condition, and displays on the display unit only the first trigger contact of the dissatisfaction of the interlock condition in a graphic language even if plural stages of interlock circuits are formed.
An interlock factor specifying method for performing execution and diagnosis of an interlock logic of a plant using a computer, the interlock factor specifying method comprising:
- determining trigger factor variables that cause a logical function value to be set to 0 or 1 in order to cause a change in an interlock condition, wherein one of the trigger factor variables which is a first cause of the interlock condition change is identified as a first trigger factor variable;
- reconfiguring, even if multiple stages of interlock conditions are formed, a logical function including only the first trigger factor variable of the trigger factor variables of the first cause of the interlock condition change;
- and
- displaying in a graphic language only the first trigger factor variable of the trigger factor variables of the first cause of the interlock condition change.
Dependencies are inferred from the claim text.