Patent ID: 9049097
Filing Date: 2015-06-02
Classification: H04L,Y04S

Abstract:
1. A communication management apparatus that manages transmission of data in a network in which a plurality of communication nodes are connected in a star shape or a line shape by an Ethernet (registered trademark) cable, the communication management apparatus comprising: a network-presence-check processing unit that performs a network presence check processing by acquiring, from the communication nodes, the communication nodes present in the network and a connection relation among the communication nodes and generating network presence information; a token-circulation-order determining unit that determines token circulation order using the network presence information such that a number of times a token frame, which is a transmission right of data, passes a transmission line between a pair of the communication nodes adjacent to each other during transmission from a predetermined communication node to the communication node is minimized and based on the determined token circulation order, generating a routing table using port numbers of the respective communication nodes, wherein the generated routing table forms a path leading from a master station to a lowest-order communication node of slave stations and iteratively back to the master station by covering the communication nodes on each level prior to moving to a higher level leading from the lowest-order communication node back to the master station; a setup processing unit that notifies, based on the token circulation order, each of the communication nodes in the network of information concerning a token circulation destination that is a communication node to which the transmission right is given after the communication node; a token-frame processing unit that compares transmission right acquiring apparatus information in the received token frame and an address of the communication management apparatus and determines whether the transmission right is obtained and, when the transmission right is obtained, after transmission of a data frame by a data-frame-communication processing unit, transmits another token frame in which, based on the token circulation order, a next communication node is set in the transmission right acquiring apparatus information; and the data-frame-communication processing unit that receives the data frame from the other communication nodes and, when the transmission right is acquired, transmits the data frame, wherein the communication management apparatus is the master station connected by the Ethernet cable to the plurality of communication nodes which are the slave stations.