| 摘要 |
PURPOSE:To reduce a computer load at normal state, by making the read corresponding to the change of measuring points possible by comparing the difference between values at this time and previous time with a set value at each scanning point of time and setting the scanning period for the next time. CONSTITUTION:A central operation processor 12 calculates and scans analog values inputted from an analog input device 11 based on various information stored in a main storage device 13 and an auxiliary storage device 14. The scanning period is divided into a plurality of ranks having different length. The difference between a value read at this time and a value read at the previous scanning period is obtained and compared with a preset change limit value (rank-up limit value). If the difference is smaller than the set value, the scanning period at the next time is made unchanged. When larger, the rank is increased and the scanning period of the next time is reduced. |
