摘要 |
A data transmission system for a LAN has a number of nodes connected in a ring or bus network. Each node has a transmit-receive circuit, a RAM, a CPU, a self node address switch, and an interface control. The frequency of adjacent node retrieval processing operation is set to be high in an initial period after the node is powered, and is set to be low thereafter. A new node added to the network can obtain a communication right within a relatively short period of time. Each node or the system can also have a maximum node address switch to allow the CPU to discriminate the current maximum address within the network. A node to be assigned with the communication right next can be discriminated fast. First and second downstream node addresses can also be stored in the RAM to allow the node to assign the communication right to the second downstream node in case the first downstream node has failed due to power failure or the like. Node address management can be performed by adding a sending origin address to the communication right, so that each node can discriminate the system configuration.
|