Patent application number | Description | Published |
20090086653 | HIGH-INTEGRITY SELF-TEST IN A NETWORK HAVING A BRAIDED-RING TOPOLOGY - 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. | 04-02-2009 |
20090116502 | EFFICIENT TRIPLE MODULAR REDUNDANCY ON A BRAIDED RING - One embodiment comprises a network that includes a plurality of bi-directional links and a plurality of nodes. Each node is communicatively coupled to two neighbor nodes and to two skip nodes using the plurality of bi-directional links. Three neighboring nodes of the plurality of nodes form a triple modular redundant (TMR) set having a first end node, a second end node, and a center node, the first end node configured to transmit output data in a first direction and the second end node configured to transmit output data in a second direction. At least one of the plurality of nodes that is not in the redundant set determines the integrity of data received from the redundant set based on at least: (i) a comparison of data received on a first logical communication channel from a respective first neighbor node with data received on the first logical communication channel from a respective first skip node; (ii) a comparison of data received on a second logical communication channel from a respective second neighbor node with data received on the second logical communication channel from a respective second skip node; and (iii) a comparison of data received on the first logical communication channel from one of the respective first neighbor node and the respective first skip node with data received on the second logical communication channel from one of the respective second neighbor node and the respective second skip node. | 05-07-2009 |
20090141744 | AUTOCRATIC LOW COMPLEXITY GATEWAY/ GUARDIAN STRATEGY AND/OR SIMPLE LOCAL GUARDIAN STRATEGY FOR FlexRay OR OTHER DISTRIBUTED TIME-TRIGGERED PROTOCOL - 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. | 06-04-2009 |
20100281130 | COMMUNICATION METHOD AND APPARATUS FOR THE EFFICIENT AND RELIABLE TRANSMISSION OF TT ETHERNET MESSAGES - 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. | 11-04-2010 |
20100284301 | DYNAMIC FAULT-TOLERANT CONFIGURATION SUPPORT AND RE-CONFIGURATION OF A BRAIDED RING NETWORK - 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. | 11-11-2010 |
20110138080 | METHOD FOR SYNCHRONIZING LOCAL CLOCKS IN A DISTRIBUTED COMPUTER NETWORK - 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. A component that is configured to consume a synchronization message will delay a received synchronization message upon reception for a duration that is calculated by an a priori configured value for the maximum transmission delay minus the value of the sum of all delay values added to the received message before further usage of the message in the synchronization process of said component. | 06-09-2011 |
20110173347 | METHOD FOR SYNCHRONIZING LOCAL CLOCKS IN A DISTRIBUTED COMPUTER NETWORK - 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. All end systems that are configured as Synchronization Master periodically send coldstart frames in one of the unsynchronized states and react to the reception of a coldstart frame by sending a coldstart acknowledgment frame a configurable first timeout after the reception of the coldstart frame on all replicated communication channels, provided that the end system is in a state in which the synchronization state machine defines a transition for coldstart frames, and where said first timeout is reset when a consecutive coldstart frame is received before the coldstart acknowledge is sent. All end systems that are configured as Synchronization Master react to the reception of a coldstart acknowledgment frame by starting a configurable second timeout, provided that they are not already executing said first timeout, and entering a synchronized state when said second timeout expires. | 07-14-2011 |
20130142204 | COMMUNICATION METHOD AND APPARATUS FOR THE EFFICIENT AND RELIABLE TRANSMISSION OF TT ETHERNET MESSAGES - 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. | 06-06-2013 |