Abstract: The goal of the present invention is to improve the useful data efficiency and reliability in the use of commercially available ETHERNET controllers, in a distributed real time computer system, by a number of node computers communicating via one or more communication channels by means of TT ETHERNET messages. To achieve this goal, a distinction is made between the node computer send time (KNSZPKT) and the network send time (NWSZPKT) of a message. The KNSZPKT must wait for the NWSZPKT, so that under all circumstances, the start of the message has arrived in the TT star coupler at the NWSZPKT, interpreted by the clock in the TT star coupler. The TT star coupler is modified, so that a message arriving from a node computer is delayed in an intelligent port of the TT star coupler until the NWSZPKT can send it precisely at the NWSZPKT into the TT network.

Abstract: A computer system includes at least two COTS processor cores and an evaluating device connected to the at least two COTS processor cores for evaluating output signals output by means of the at least two COTS processor cores. The evaluating device includes a comparator for pair-wise comparison of the respective generated output signals with each other. The comparator also outputs a comparison signal corresponding to the respective comparison of the output signals.

Abstract: A method of configuring a node comprises receiving a first message having a count field value from a first direct link; receiving a second message having a count field value from a first skip link; adjusting the count field value in the first message by a first adjustment amount; adjusting the count field value in the second message by a second adjustment amount; comparing the adjusted count field value in the first message with the adjusted count field value in the second message; if the adjusted count field value in the first message matches the adjusted count field value in the second message, using the adjusted count field value in the first message to determine a node identity for the node; and processing subsequent messages based on the node identity.

Abstract: A communication device comprises first and second circuits to implement a plurality of ports via which the communicative device is operable to communicate over a plurality of communication channels. For each of the plurality of ports, the communication device comprises: command hardware that includes a first transmitter to transmit data over a respective one of the plurality of channels and a first receiver to receive data from the respective one of the plurality of channels; and monitor hardware that includes a second receiver coupled to the first transmitter and a third receiver coupled to the respective one of the plurality of channels. The first circuit comprises the command hardware for a first subset of the plurality of ports. The second circuit comprises the monitor hardware for the first subset of the plurality of ports and the command hardware for a second subset of the plurality of ports.

Abstract: A special node is used in a distributed time-triggered cluster. The special node comprises protocol functionality to establish a time base to use in communicating with a plurality of end nodes and to source timing-related frames to the plurality of end nodes in accordance with the distributed time-triggered communication protocol. The protocol functionality establishes the time base without regard to any timing-related frame sourced from any of the plurality of end nodes. In one embodiment, the protocol functionality of the special node is implemented in a low complexity manner. In one embodiment, the cluster comprises a star topology and the special node performs at least one of semantic filtering and rate enforcement. In another embodiment, the cluster comprises a bus or peer-to-peer topology and each end node is coupled to the communication channel using a low-complexity special local bus guardian.

Abstract: A distributed control system comprises a first network section comprising one or more control nodes containing control logic operable to perform control function computations; a second network section, wherein the second network section comprises; a plurality of additional nodes responsive to the one or more control nodes in the first network section, each of the plurality of additional nodes communicatively coupled to two neighbor nodes and to two skip nodes using a plurality of links; first and second gateway interfaces each coupled to the first and second network sections and each operable to interface the first network section to the second network section; wherein the first network section is operable to communicate signals using a first communication protocol; and wherein the plurality of nodes in the second network section are operable to communicate signals over the plurality of links using a second communication protocol that is different from the first communication protocol.

Abstract: A method of communicating node status in a star network comprising a hub and a plurality of nodes comprises sending a first message to the hub from a first node included in the plurality of nodes; forwarding the first message from the hub to at least one second node included in the plurality of nodes; communicating status information to the hub from the at least one second node after receiving at least a portion of the first message at the at least one second node; compiling a status vector based on the status information received from each of the at least one second nodes; and sending the status vector from the hub to at least the first node.

Abstract: The invention relates to a method for synchronizing local clocks in a distributed computer network, where said computer network consists of a number of end systems and at least two switches. Each end system is connected to at least two switches via bi-directional communication links. A configured subset of end systems and switches executes the method in form of a synchronization state machine. The state machine uses at least three different frame types. The states in the state machine are either said to belong to an unsynchronized set of states or belong to a synchronized set of states.

Abstract: The invention relates to a method for synchronizing local clocks in a distributed computer network, where said computer network consists of a number of components that are connected to each other via bi-directional communication links, characterized in that an a priori configured set of components of the network generates synchronization messages and sends these synchronization messages to the network. An a priori configured set of components consumes the generated synchronization messages. One or more message-relaying components in between a component that generates a synchronization message and the component that consumes the synchronization message will add a delay value to the synchronization message reflecting the delay imposed by the message-relaying component.

Abstract: Systems and methods for network clock synchronization are provided. In one embodiment, a method for clock synchronization in a braided ring network comprises: providing a schedule for a braided ring network comprising a plurality of nodes, wherein at least two nodes comprise a self-checking pair of a first node and a second node, the first node performing a method comprising: determining when a first rendezvous message is received from the second node; when the second rendezvous message is received, calculating a time difference between the send instance of the first rendezvous message and a local time; when the time difference is not greater than a reference bound, calculating a sending point for transmitting a synchronization message, wherein the sending point is calculated based on the time difference; and selectively sending the synchronization message to the braided ring network when the sending point is reached based on the time difference.

Abstract: A half-duplex communication network comprises a plurality of communication links, each link being configured a priori to communicate in one direction; and a plurality of nodes, each node coupled to a first and second direct neighbor nodes and a first and second skip neighbor nodes via the plurality of communication links. Each node comprises propagation logic adapted to arbitrate conflicts between concurrent messages based on at least one of higher level policies and a comparison between a priority of each message, wherein each node is adapted to communicate a message without waiting to determine if another node is transmitting another message with a higher priority.

Abstract: A method of configuring a node comprises receiving a first message having a count field value from a first direct link; receiving a second message having a count field value from a first skip link; adjusting the count field value in the first message by a first adjustment amount; adjusting the count field value in the second message by a second adjustment amount; comparing the adjusted count field value in the first message with the adjusted count field value in the second message; if the adjusted count field value in the first message matches the adjusted count field value in the second message, using the adjusted count field value in the first message to determine a node identity for the node; and processing subsequent messages based on the node identity.

Abstract: The goal of the present invention is to improve the useful data efficiency and reliability in the use of commercially available ETHERNET controllers, in a distributed real time computer system, by a number of node computers communicating via one or more communication channels by means of TT ETHERNET messages. To achieve this goal, a distinction is made between the node computer send time (KNSZPKT) and the network send time (NWSZPKT) of a message. The KNSZPKT must wait for the NWSZPKT, so that under all circumstances, the start of the message has arrived in the TT star coupler at the NWSZPKT, interpreted by the clock in the TT star coupler. The TT star coupler is modified, so that a message arriving from a node computer is delayed in an intelligent port of the TT star coupler until the NWSZPKT can send it precisely at the NWSZPKT into the TT network.

Abstract: A network comprises a plurality of nodes; a plurality of bi-directional point-to-point communication links, wherein a priority-based arbitration scheme is used to communicate over each of the plurality of point-to-point links; and a hub that is communicatively coupled to each of the plurality of nodes via the plurality of point-to-point links; wherein when the hub determines that one or more of the nodes is transmitting a message via the hub, the hub selects which node's message should be forwarded to the other nodes based, at least in part, on the priority-based arbitration scheme and forwards the selected node's message to the other nodes with elevated priority.

Abstract: In one embodiment, a node comprises an interface to communicatively couple the node to a plurality of independent communication links. The node changes the mode in which the node operates when the node receives an indicator on a plurality of the independent communication links.

Abstract: In one embodiment, a network comprises a plurality of nodes that are communicatively coupled to one another using bidirectional, half-duplex links. The network has a logical first channel over which data is propagated along the network in a first direction and a logical second channel over which data is propagated along the network in a second direction. For a given period of time, at least one of the plurality of nodes is scheduled to be a transmitting node that transmits data on both the first channel and the second channel. A first subset of the nodes not scheduled to transmit during the period are scheduled to relay data received from the first channel along the first channel. A second subset of the nodes not scheduled to transmit during the period are scheduled to relay data received from the second channel along the second channel.

Abstract: A method for authenticating a message in a time division multiple access network is provided. The method includes receiving a message from an active relaying component, inspecting a value in the message inserted by the active relaying component, and comparing the value with an expected value based on a transmission schedule.

Abstract: In one embodiment, a system comprises a plurality of nodes that are communicatively coupled to one another. Each of the plurality of nodes, in the absence of any faults, is communicatively coupled to at least a first neighbor node and a first neighbor's neighbor node and a second neighbor node and a second neighbor's neighbor node. When at least a first clique and a second clique exist within the plurality of nodes and a first node included in the first clique successfully receives a synchronization message associated with the second clique from the first neighbor node of the first node and the first neighbor's neighbor node of the first node, the first node does the following. The first node defects to the second clique and synchronizes to the synchronization message. The first node also communicates a join message to at least the second neighbor node of the first node and the second neighbor's neighbor node of the first node.

Abstract: In one embodiment, a node comprises an interface to communicatively couple the node to a first channel. The first channel communicatively couples the node to a first neighbor node and a first neighbor's neighbor node in a first direction. When the node is operating in an unsynchronized mode: the node relays, along the first channel, for a relay period, data received from the first neighbor node that was sourced from that first neighbor node and, after relaying the data received from the first neighbor node that was sourced from that first neighbor node and for a block period, the node blocks data received from the first neighbor while the node relays, along the first channel, data received from the first neighbor's neighbor node.

Abstract: A distributed control system comprises a first network section comprising one or more control nodes containing control logic operable to perform control function computations; a second network section, wherein the second network section comprises; a plurality of additional nodes responsive to the one or more control nodes in the first network section, each of the plurality of additional nodes communicatively coupled to two neighbor nodes and to two skip nodes using a plurality of links; first and second gateway interfaces each coupled to the first and second network sections and each operable to interface the first network section to the second network section; wherein the first network section is operable to communicate signals using a first communication protocol; and wherein the plurality of nodes in the second network section are operable to communicate signals over the plurality of links using a second communication protocol that is different from the first communication protocol.