| 摘要 |
<p>PROBLEM TO BE SOLVED: To decrease resending processing by maintaining a stable line state, resulting in shortening of response time. SOLUTION: Before cyclically exchanging data with a slave station 12, a master station 11 detects the state of a line with the slave station 12 and when the slave station 12 does not have the stable line state as a result, the subscription/release information of the relevant slave station in a slave status table is made into non-subscription but when the slave station has a prescribed line state, the subscription information of the slave station is made into subscription. Thus, in the case of refreshing an I/O with the slave station 12, it is performed based on the subscription/release information in the slave status table so that the stable line state can be provided.</p> |
