Abstract: A system for monitoring, controlling, and locating portable computerized devices performing remote diagnostic analysis of control networks. The portable, wireless equipment includes computerized display device connected to a wireless intermediary device for allowing a wireless connection to be made to a control network. The computerized diagnostic device may be embodied as a personal digital assistant (PDA) having a graphical screen display, on which may be displayed the network nodes and connections of the control network presented against a backdrop of a transit vehicle or other facility shown in three-dimensional, rotatable images. The wireless equipment may allow the operator to force individual system components to output states, and provide for real time monitoring. The portable, wireless equipment is programmed with information pertaining to the connections and locations of the components in the control network, thereby simplifying diagnosis or testing by the operator.

Abstract: A network node includes a housing in which the electronics of the network node are contained, the housing having an external port to which a plug-in module can be physically attached. The plug-in module contains a readable memory which, when the plug-in module is attached, allows electronic interconnection between the electronics of the network node and the readable memory. The readable memory stores a unique node identifier which becomes associated with the node, and can also store functional program code for the particular node. Thus, a node can be easily and rapidly replaced or reprogrammed, without the need for specialized equipment to download the node identifier or functional program code, and without the possibility of erroneous manual entry of the node identifier. In operation, the node reads in its node identifier from the appropriate address of the readable memory, and thereafter sends and receives communications in accordance with the node identifier it has read out from the plug-in module.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A multi-tier, master-slave control network has a matrix architecture for facilitating monitoring, command and control of the mid- and lower-tiers of the control network. A supervisory network is connected to a hierarchical master-slave control network, and includes a set of supervisory nodes connected to various different buses of the main hierarchical master-slave control network. In one embodiment, the supervisory network comprises a multi-master data bus, and each of the supervisory nodes can control and communicate across the supervisory data bus in a manner similar to a local area networks such as an Ethernet. In another embodiment, the supervisory network is a master-slave network, with a supervisory master node controlling a set of supervisory slave nodes, each of which connects to one of the lower-tier buses. The matrix architecture created by the addition of the supervisory network allows convenient monitoring of the lower-tier buses by the first-tier master node.

Abstract: A system for facilitating diagnosis and maintenance of one or more control networks located on a mobile conveyance comprises one or more wireless ground stations configured to communicate over a wireless communication channel with a control network via a wireless interface. A local area computer network receives and responds to messages to or from the control network via the wireless ground stations. The local area computer network comprises one or more user terminals, a server computer, a database comprising diagnostic information relating to said control network, and, optionally, a replacement parts database and/or job auction database. The local area network further includes a wide area network interface, which allow either additional diagnostic information relating to the control network to be retrieved, or parts to be manually or automatically ordered from remote vendor sites.

Abstract: A multi-tier, master-slave control network having multiple buses comprises a master node and a plurality of slave nodes operating over each of the multiple buses. Each master node comprises a downlink transceiver, and each slave node comprises an uplink transceiver. All of the nodes in the control network are connected in a continuous loop configuration with each segment of the loop comprising a cable connector of either a first type (feed thru) or a second type (crossover). Each cable connector comprises a pair of signal wires for each bus. The type of cable connector between any two adjacent nodes in the loop is related according to which of the uplink or downlink transceiver should be connected to which bus.

Abstract: A control network has a bus to which is connected a master node and a plurality of slave nodes in a loop configuration. Each of the master node and slave nodes has a transceiver connected to the bus through a shunt circuit. The shunt circuit comprises a switch (such as a relay) in parallel circuit configuration with an impedance element (such as resistor). The switch is operated under control of the node and under normal conditions remains closed, thereby allowing signals to be carried freely over the bus. When a fault occurs, each of the nodes opens its switch, causing the separate portions of the bus to become isolated. The master node then instructs each slave node, starting with the closest slave node, to close its switch. When a slave node fails to respond, the fault location has been detected. The master node repeats the process for the opposite direction of the loop. Operation then continues, with the slave node nearest the fault remaining isolated.

Abstract: A multi-tier, master-slave control network has at least three data buses. A first-tier master node and a plurality of first-tier slave nodes are connected to a main data bus. One or more first-tier slave nodes are connected to secondary data buses. The secondary data buses are connected to second-tier slave nodes, and the first-tier slave node connected to the secondary data bus acts as a master node with respect to the secondary data bus. One or more second-tier slave nodes may be connected to tertiary data buses to provide another layer of control nesting. The tertiary data buses are connected to third-tier slave nodes, and the second-tier slave node connected to the tertiary data bus acts as a master node with respect to the tertiary data bus.

Abstract: A multi-tier, master-slave control network having redundant backup for a master node in which the slave nodes are provided with means for detecting a failure of the master node and for taking over for the master node in such circumstances. The master node and slave nodes are connected to a common bus. Each of the slave nodes has an uplink transceiver and a downlink transceiver, with the downlink transceiver ordinarily isolated by switches from the common bus. Each of the slave nodes has a timer programmed with a separate failure mode detection time period. When a slave mode fails to receive control messages from the master node for a period exceeding its programmed failure mode detection time period, the slave node takes over for the master node. Because each slave node has a separate failure mode detection time period, a priority is established in which the slave nodes will take over for the master node, and redundant master backup control is provided.

Abstract: A multi-tier, master-slave control network having multiple buses comprises a master node and a plurality of slave nodes operating over each of the multiple buses. Each master node comprises a downlink transceiver, and each slave node comprises an uplink transceiver. All of the nodes in the control network are connected in a continuous loop configuration with each segment of the loop comprising a cable connector of either a first type (feed thru) or a second type (crossover). Each cable connector comprises a pair of signal wires for each bus. The type of cable connector between any two adjacent nodes in the loop is related according to which of the uplink or downlink transceiver should be connected to which bus.