| 摘要 |
<p>PURPOSE:To shorten the investigation time of a discrepancy cause by adding a sequence number to status change data, providing an input/output counter to count the number of times to generate status change data, the number of times of reception and transmission and the number of times to be updated at a master station and a slave station respectively, and comparing these measured values with each other. CONSTITUTION:A sequence number is added to condition change data by an adding means 22 to be updated and stored into a data base 23, on the other hand, transmitted to a master station 27 to compare a previous sequence number with a present one at a comparing means 25. The comparing means 25 compares a value to add or subtract a constant value to or from a previous sequence number with a present sequence number, and only when both are coincident, the sequence number and the condition change data are updated and stored to a data base 26. Consequently, since the time series generation order of condition change data can be discriminated by a sequence number, a simultaneous management can be executed. A missing to send a sequence number can be also checked by regularly comparing sequence numbers between a master station 27 and slave stations 241-24n.</p> |
