| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a distributed control system for achieving both synchronicity and continuity of a control arithmetic operation in a plurality of field controllers. <P>SOLUTION: A Tick adjustment part 24 adjusts the time of a control clock 21a of a field controller 2A according to a network time obtained through a control network 5. When the control clock 21a is delayed, the control cycle is reduced compared with the original cycle, so that the control scan timing is gradually shifted, and a control state in the absence of power failure can be obtained. When the time indicated by the control clock 21a coincides with the time indicated by a network clock 23, the control cycle is restored to the original control cycle T. <P>COPYRIGHT: (C)2010,JPO&INPIT |
