JP2795867B

PURPOSE:To attain proper plant monitor by adjusting a display element of a system diagram to be displayed in response to the size of the display area. CONSTITUTION:A display information filtering means 12 selecting a display element is provided based on the storage contents of a display mode storage means 4 and the magnification set from an interactive equipment 1 and a display means 3 forms a display data of a displayed system diagram based on the display information inputted from a display information filtering means 12 and the storage content of a plant state storage section 7. Then the reduction rate of the system diagram is discriminated based on the identification information of the display area informed from an interactive means 2, the reduction display data reducing the formed display data by the reduction rate is formed and the data is outputted to the interactive device 1. Thus, the system diagram selected by the operator is displayed to the interactive device 1 while being reduced so as to be housed in the designated display area and the content of the system diagram is simplified in response to the reduction rate.