| 摘要 |
<p>PURPOSE:To surely recognize the flexible change of process data by providing a history file table consisting of a history file to store past data and a pointer indicating the file in which the latest data should be stored. CONSTITUTION:The process data is read at every pulse input processing cycle by an input/output means. And differential data between a value read at this time and the value read at a preceding time is obtained, and furthermore, an estimation value at this time is obtained by adding the differential data at this time on a preceding estimation value. In an initial stage where the processing at this time is the first processing of a pulse input processing, the differential data at this time is stored in all of the history files 31 of corresponding points, and the value of the pointer 32 is designated as the maximum value of the history file. Also, in an ordinary stage where it is the pulse input processing for the second and after time, the differential data at this time is stored in the history file 31 indicated by the pointer 32, and after that, the sum of all of the data in the history file 31 is divided by the maximum value of the history file. In such a way, the data can be obtained as a momentary value at this time.</p> |
