| 摘要 |
<p>PURPOSE:To prevent a communication from being disconnected at the time of a changeover from the bus of a living system to the bus of a standby system by switching the information channel without switching a line when a trouble, etc., are generated to the line. CONSTITUTION:When the trouble is generated at a point 30 in a subnetwork 1a, node devices 3a and 4a prepare packets A, and they are sent on the signal channels of lines 8 and 10. Line switching devices 18a and 19a inactivates an information channel B2 of the lines 8 and 10, activate the information channel B2 of lines 9 and 11, prepare packets B, and send them on the signal channels of the lines 9 and 11. When node devices 5a and 6a receive the packets B, they switch the information channel B2 of the lines 9 and 11 to the bus of the living system. In such a case, since the information channel B2 set to a line 13 between the node device 6a and a line switching device 20a of a subnetwork 2a is not inactivated, the communication between a communicating device 24 and a communicating device 23 in which the standby systems are not set can be continued.</p> |
