Data acquisition system and storage medium for storing the data used in the same

摘要

A next update prediction time storage section receives the present time from a clock section and transfers part or all of the links whose corresponding next update prediction times are earlier than the present time to a transmission/reception section. The transmission/reception section communicates via a network and acquires the data specified by a link. An update history storage section extracts the latest update time when information on the latest update time exists in the acquired data. The update history storage section adds the extracted latest update time to the update history corresponding to the link and calculates the next update prediction time from the added and updated update history. The update history storage section sends the calculated next update prediction time to the next update prediction time storage section. The next update prediction time storage section replaces the next update prediction time corresponding to the link with the calculated next update prediction time. A link extraction section extracts the link group from the transferred data and transfers the link group to a link stack section. The link stack section sends each of the extracted link groups to the next update prediction time storage section, only when it has not been registered yet.