| 摘要 |
<p>PURPOSE:To intuitively recognize the future rate of change by calculating a rate of change with a previous input value concerning the instantaneous value of a process, making a process quantity and the rate of change into two-dimensional data, determining the line segment of a trend from the coordinate value and displaying the instantaneous value and a change width in two-dimension. CONSTITUTION:A trend display device 15 fetches a distributing reservoir water level measured by a water level gage 3 provided at a distributing reservoir water level 1 into an input device 5. Next, the instantaneous value of the water level WL is stored through a converter 6 to a time series file 7. Thus, a change arithmetic unit 8 indexes latest two data from the file 7, calculates a water level change width and stores it into an instantaneous table 9. Next, a coordinate converter 10 indexes a table 9, converts it to the coordinate value on a display device 16 and stores it into a coordinate table 11. A vector arithmetic device 12 determines the direction of the present line of a trend based on the table 11, stores it into a displaying table 13, displayed by two-dimension at the device 6 and the change can be intuitively recognized.</p> |
