| 摘要 |
<p>PURPOSE: To retrieve operation data in a short time by time-sequentially arranging the operation data of a previous day operation history data base for each data number in an optical disk preserving part and preserving those data in an optical disk. CONSTITUTION: An operation data order change part 15 is so provided as to continuously and time-sequentially arrange the operation data in a previous day operation history data base 8 for each data number. When preserving operation data, which are not time-sequentially and continuously arranged for each data number in the previous day operation history data base 8, in an optical disk 12, those data are continuously and time-sequentially rearranged for each data number by the operation history data order change part 15. Therefore, an operation history data preserving part 11 preserves those data in the optical disk 12 as data continuous and time sequential for each data number. Accordingly, when retrieving the operation data to be used for a timewise continuous trend graph, for example, the operation data can be retrieved in a short time.</p> |
