Abstract: A relay device and the like are provided which are capable of easily transmitting/receiving information among information processors connected on buses whose information transmission standards are different from each other. A bridge B1 for connecting buses BS1 and BS2 whose information transmission standards are different from each other includes: an operation unit (11) for performing an operation of instructing an operation of an apparatus connected to any of the buses BS; a message generator 5 for generating a control message corresponding to the instructed operation; and a packet transmitter/receiver (7, 8) for transmitting the generated control message to a target apparatus via the bus BS to which the target apparatus is connected.

Abstract: A relay device and the like are provided which are capable of easily transmitting/receiving information among information processors connected on buses whose information transmission standards are different from each other. A bridge B1 for connecting buses BS1 and BS2 whose information transmission standards are different from each other includes: an operation unit (11) for performing an operation of instructing an operation of an apparatus connected to any of the buses BS; a message generator 5 for generating a control message corresponding to the instructed operation; and a packet transmitter/receiver (7, 8) for transmitting the generated control message to a target apparatus via the bus BS to which the target apparatus is connected.

Abstract: A network connection control device is provided that is capable of quickly and accurately executing the process for connection when connecting together networks that both comply to the IEEE 1394 standard. After networks that both comply to the IEEE 1394 standard are connected together and a bus reset occurs, as the contents of the route maps M1A, M1B, M2A and M2B that are stored in the respective portals 1A, 1B, 2A and 2B are updated, GUID, which indicates any one of the portals in the network group G, is used to generate bus ID information for the newly created bus.

Abstract: A bridge is provided with a first portal connected to a first communication line forming one part of a network for transmitting/receiving information via the first communication line, and a second portal connected with a second communication line forming the other part of the network for transmitting/receiving information via the second communication line. These first and second portals can transfer information received, to each other. When one of the first and second portals receives, in case a connection has already been established on the network including that bridge, environment updating information for updating the using environment of the connection, via one of the first and second communication lines, one of the first and second portals transfers the environment updating information received, to the other. The other of the first and second portals updates the using environment of the other of the first and second communication lines in accordance with the environment updating information transferred.

Abstract: A data transmission system capable of ensuring proper operation even when any nodes-to-bus connection, which is not allowed by restrictions, is made. The system implements data transmission among a plurality of nodes mutually connected by a cable serving as a bus. The system includes a first process for initializing a control process on the nodes to the bus in accordance with a change in an electrical connection of the bus, a second process of detecting a connection topology of the nodes, and a third process for identifying each node to be connected to the bus. A forbidden connection detecting process is provided for detecting if there is a loop connection path of the nodes on the bus and handling operations are provided for executing handling in accordance with a result of detection by the forbidden connection detecting process.