Abstract: A method A and apparatus for monitoring and switching over from a primary bus to a back-up bus in a network having a master node and at least one slave node, the primary bus and the back-up bus each interconnecting the master node and the at least one slave node. The method includes periodically sending via the back-up bus from the master node to each of the slave nodes a master test packet containing a master address of the master node on the back-up bus and sending on the back-up bus from the at least one slave node to the master node and in response to receiving the master test packet, a slave test packet containing a slave address of the at least one slave node on the back-up bus.

Abstract: A method for initializing a communication network in a train including a plurality of cars, the network comprising a train bus, a train bus master on one of the cars and a train bus slave on each other car connectable to the train bus master by the train bus for communicating with the train bus master. The method includes determining whether the one car with the train bus master is located at one end of the train or is in the middle of the train. The method further includes transmitting first messages between the train bus master and each train bus slave, respectively, located in one direction for assigning an address to each train bus slave located in that one direction and acquiring data at the train bus master uniquely identifying the respective train bus slaves in that one direction.

Abstract: A method for placing a multi-car train with a communication network in an energy saving layup mode, the communication network having a master node interconnected to at least one other node via a train bus, the train having a head car for carrying the master node and at least one other car for carrying the at least one other node with an intelligent subsystem unit coupled to the train bus by the other node. The method includes transmitting a shutdown signal to the master node; sending in response to the shutdown signal a shutdown message from the master node to the at least one other node after a predetermined amount of time; and shutting down power to the intelligent subsystem unit in response to receiving the shutdown message at the at least one other node.

Abstract: A method for controlling power consumed by a plurality of subsystems on a multi-car train having a plurality of power supplies connected in parallel for supplying power to the subsystems. The train has a train wide communication network which includes a vehicle bus in each car of the train communicating with the power supplies and subsystems on the car, a train bus extending through the entire train, and communication nodes in each car interconnecting the train bus with each one of the vehicle buses. One of the communication nodes in one of the cars constitutes a master node and the other communication nodes in the other cars constitutes slave nodes, each slave node communicating status information about power supplies and subsystems on its vehicle bus to the master node and communicating control information to the power supplies and subsystems on its vehicle bus.

Abstract: A method and apparatus for determining an overall master node for an overall communication network with a serial bus, wherein the overall communication network comprises an original communication network connected to a new communication network via a serial bus with high level data link control (HDLC) packets. The method and apparatus are especially applicable to trainline monitor systems since such systems are frequently divided up and rearranged because their associated trains are frequently divided up and rearranged. The method involves performing a series of steps in order to relinquish mastership of certain master nodes placing those master nodes in an inactive state and making a desired master node an overall master node of the resulting overall trainline monitor system, and the apparatus involves a corresponding series of means for performing these steps.

Abstract: A system for testing a plurality of subsystems in a multi-car train over a train-wide communications network includes at least one master station and a plurality of slave stations interconnected by the train-wide communications network, each station collecting status and diagnostic information from associated slave subsystems and providing the information upon request. A portable test unit is provided for testing the subsystems by requesting status and diagnostics information about at least one of the plurality of slave subsystems over the communications network. A diagnostic interface is provided in the at least one master station for interfacing the portable test unit to the master station to facilitate transmission of data between the portable test unit and the train-wide communications network.