| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To judge the abnormality of a controller and detect any illegal access by monitoring data flowing through a network to which the controller is connected, and to announce them through the network to the outside of the job site. <P>SOLUTION: Controllers 101A to 101C and an operator console 105 are connected like a star through a repeater 104. An apparatus for diagnosing plant network integrity is constituted by directly connecting a data collection means 110 to the repeater 104, and directly connecting an inspection means 120 to a data collection means 110. The data collection means 110 receives and collects all the frames transmitted to a plant network. A fixed cyclic data inspection means 130 of the inspection means 120 inspects a frame by comparing a frame transmitted in a fixed cycle with a frame reference information recorded beforehand. <P>COPYRIGHT: (C)2004,JPO</p> |
