| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a plant system that can be diagnosed as to the soundness of transmission in a quick and reliable way, and a method for diagnosing its transmission. <P>SOLUTION: The plant system comprises a master controller 1 that creates a heartbeat signal for diagnosis of transmission; a slave controller 2 operated by instructions of the master controller 1; and a network device 3 that transfers signals between the master controller 1 and the slave controller 2. The slave controller 2 has a means for reversing and outputting a return heartbeat signal to the master controller when detecting the edge of the heartbeat signal transmitted from the master controller 1. The master controller 1 has a means for reversing and outputting the next reference heartbeat signal to the slave controller 2 when detecting the edge of the return heartbeat signal from the slave controller 2, and a means for measuring the pulse width of the reference heartbeat signal of the master controller 1. When the pulse width is equal to or greater than a preset threshold, the transmission is determined to be abnormal. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
