| 摘要 |
<p>PROBLEM TO BE SOLVED: To ensure communication by changing the master nodes even when a fault takes place in one channel or a master node. SOLUTION: The master node is decided among nodes 110 to 113 in the following manner. First, each node transmits the preliminarily set node priority of present node to the next nod through 0-system and 1-system transmission paths. The next node that receives the node priority sends the node priority of the present node to the next node when the node priority of the present node is higher than the received node priority and sends the received node priority as its is when the node priority of the present node is lower than the received node priority. When the node priority of the present own node is higher continues for a prescribed times, the present node is defined as a dummy master node, and when both 0- and 1-system are a dummy master node, the node is defined as a master node. Even though a fault takes place in the channel and the master node, a node whose node priority is the highest among sound nodes is defined as a master node to ensure communication.</p> |
