JP2779574B

PURPOSE:To quickly perform data retrieving on a display screen and to reduce the load of an operator and supervisor. CONSTITUTION:A scroll bar 14, whose length matches the capacity of a memory in which data showing plant conditions are stored, is set in part of a window 12 and a position in the scroll bar 13 is correlated with a data storage position in the memory and a series of data stored in the data storage position of the memory which corresponds to the position designated by a pointer 14 are displayed on a plant monitoring screen. In that case, the position in which a specific one of the data is stored is displayed in relation to the scroll bar 13 by means of a time tag 17. An operator and supervisor can surely perform retrieval without missing the required data by moving the pointer 14 to the position of the specific data indicated by the time tag 17 even if the speed of scroll operation on the screen is increased.