| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to store the newest and always correct data of fixed volume even when the time of a timer circuit is corrected or changed in error. SOLUTION: Data files 17 in which data of prescribed volume successively collected from a target 12 to be monitored and collection time obtained from a timer circuit 15 are written are successively prepared and successively stored in a data storage part 18, and when the number of data files 17 stored in the storage part 18 exceeds a previously determined regulated number necessary for data storage, future time exists in the collection time of respective stored data files 17 or not is judged. When future time does not exist, a data file corresponding to the oldest collection time is deleted. When future time exists, a data file corresponding to the farthest future time is deleted.</p> |
