Patent ID: 7418005

Claim:
A method for optimizing a bus on a network including a plurality of communication nodes each having a plurality of ports, wherein the plurality of ports of each communication node are connected to ports of other communication nodes through corresponding signal cables on a one-to-one basis so as to allow each communication node to receive and transmit a signal from and to an adjacent communication node, the method comprising: a step of causing one of two communication nodes to be a test initiator and the other to be a test target when new connection of a signal cable is detected between the two communication nodes; a transmitting step where the test initiator adds information of a connected port, the connected port where connection of the signal cable was detected, to a loop test signal and transmits the resultant loop test signal to another communication node from a port other than the connected port; a repeating step where a communication node having a received port, the received port receives the loop test signal, adds the information of the receiving port to the loop test signal and transfers the resultant loop test signal to another communication node from a port other than the receiving port; a step of detecting generation of a loop based on the received loop test signal; a step of determining, when the loop is detected in the detecting step, a port for disconnecting the loop, based on the port information added to the loop test signal; and a step of outputting a disconnection instruction signal for inactivating a port to a communication node having the port determined in the determining step, wherein the loop test signal has a field for storing a node number, a port number and port information, in the repeating step, the information of the receiving port is compared with the port information stored in the field of the loop test signal, and when the receiving port is more preferable for disconnecting the loop, the node number, port number and port information stored in the field are replaced with a node number of a communication node having the receiving port, a port number of the receiving port and information of the receiving port, and the resultant loop test signal is transmitted to another communication node from a port other than the receiving port.