Abstract: A network for an industrial control system employs a ring topology that is normally opened by a ring supervisor at the ring supervisor. Upon failure of the network, the ring supervisor reconnects the ring to provide an alternative transmission path around the failure point. High speed operation is reconciled with the ability to use commercial switching integrated circuits through a dual communication channel of communicating a network state as either closed or open using both high-speed hardware handled beacon frames and low-speed software processed announce frames.

Abstract: The subject matter disclosed herein describes a method to allocate and prioritize data communications on an industrial control network. A transmission schedule including multiple priority windows and multiple queues is established. Each queue is assigned to at least one priority window, and each priority window may have multiple queues assigned thereto. A control device communicating on the control network transmits data packets according to the transmission schedule. Within each priority window, data packets corresponding to one of the queues assigned to the priority window may be transmitted. The data packets may be transmitted at any point during the priority window, but will only be transmitted if no data packet from a higher queue is waiting to be transmitted.

Abstract: A distributed control system and methods of operating such a control system are disclosed. In one embodiment, the distributed control system is operated in a manner in which interrupts are at least temporarily inhibited from being processed to avoid excessive delays in the processing of non-interrupt tasks. In another embodiment, the distributed control system is operated in a manner in which tasks are queued based upon relative timing constraints that they have been assigned. In a further embodiment, application programs that are executed on the distributed control system are operated in accordance with high-level and/or low-level requirements allocated to resources of the distributed control system.

Abstract: Fault-tolerant Ethernet is provided through the use of special interfaces providing duplicate ports that may be alternatively enabled with the same network address. A switching between the ports, corrects for single faults in a two-way redundant system without time-consuming reconfiguration of other end devices or the need for complex middleware in the end devices.

Abstract: Fault-tolerant Ethernet is provided through the use of special interfaces providing duplicate ports that may be alternatively enabled with the same network address. A switching between the ports, corrects for single faults in a two-way redundant system without time-consuming reconfiguration of other end devices or the need for complex middleware in the end devices.

Abstract: A distributed control system and methods of operating such a control system are disclosed. In one embodiment, the distributed control system is operated in a manner in which interrupts are at least temporarily inhibited from being processed to avoid excessive delays in the processing of non-interrupt tasks. In another embodiment, the distributed control system is operated in a manner in which tasks are queued based upon relative timing constraints that they have been assigned. In a further embodiment, application programs that are executed on the distributed control system are operated in accordance with high-level and/or low-level requirements allocated to resources of the distributed control system.

Abstract: A high-speed security device for network connected industrial controls provides hybrid processing in tandem hardware and software security components. The software security component establishes state-less data identifying each packet that requires high-speed processing and loads a data table in the hardware component. The hardware component may then allow packets matching data of the data table to bypass the software component while passing other non-matching packets to the software component for more sophisticated state analysis.

Abstract: A method and circuit for precisely synchronizing clocks in separate nodes on a communication network is provided by adjusting timestamps and related data in network messages. The circuit will allow a daisy-chain connection of the nodes and will forward time synchronization frames while accounting for delays in a manner that does not use boundary clocks, but does not depart from the IEEE 1588 standard protocol. The delays will be added on the fly to synchronization packets and the IP checksum and frame CRC will be adjusted. Deterministic data delivery and redundant data paths are also provided in a full duplex Ethernet network.

Abstract: A distributed control system and methods of operating such a control system are disclosed. In one embodiment, the distributed control system is operated in a manner in which interrupts are at least temporarily inhibited from being processed to avoid excessive delays in the processing of non-interrupt tasks. In another embodiment, the distributed control system is operated in a manner in which tasks are queued based upon relative timing constraints that they have been assigned. In a further embodiment, application programs that are executed on the distributed control system are operated in accordance with high-level and/or low-level requirements allocated to resources of the distributed control system.

Abstract: A method of precisely synchronizing clocks held in separate nodes on a communication network is provided that adjusts clock frequency based on a measure of relative clock rates and absolute clock offsets. In one embodiment, clock convergence is obtained with one synchronization session.

Abstract: Fault-tolerant Ethernet is provided through the use of special interfaces providing duplicate ports that may be alternatively enabled with the same network address. A switching between the ports, corrects for single faults in a two-way redundant system without time-consuming reconfiguration of other end devices or the need for complex middleware in the end devices.

Abstract: A transmission schedule is overlaid on the Ethernet protocol to allow use of this readily available high speed protocol for transmission of I/O data communicated in an industrial control environment and requiring a high degree of determinism. Scheduling improves load leveling and bandwidth utilization and by producing a more consistent delay may be teamed with time synchronization to produce more accurate clock synchronization.

Abstract: A controller configured to operate as at least one agent, a method of configuring a controller for operation as part of a multi-agent distributed control system, and a configuration device for so configuring a controller, are disclosed. The controller includes at least one processing device and at least one storage medium that is in communication with the at least one processing device. The at least one storage medium stores a plurality of program portions that are executed by the at least one processing device, and the plurality of program portions includes first, second and third program portions. The first program portion is capable of generating first signals that are commands to be provided to a controlled device, the second program portion is capable of governing standard agent-type functionality, and the third program portion is capable of governing application-specific agent-type functionality.

Abstract: A method and circuit for precisely synchronizing clocks in separate nodes on a communication network is provided by adjusting timestamps and related data in network messages. The circuit will allow a daisy-chain connection of the nodes and will forward time synchronization frames while accounting for delays in a manner that does not use boundary clocks, but does not depart from the IEEE 1588 standard protocol. The delays will be added on the fly to synchronization packets and the IP checksum and frame CRC will be adjusted. Deterministic data delivery and redundant data paths are also provided in a full duplex Ethernet network.

Abstract: A distributed control system employs a number of autonomous cooperative units that intercommunicate with bids and counter bids to allocate the production of a product among them. Network traffic caused by these bid messages is significantly reduced by creating as a central clearinghouse, a global resource locator that can identify autonomous cooperative units more likely to be receptive to bids from other autonomous cooperative units. Portions of the data of the global resource locator are held at the particular computers implementing the autonomous cooperative units in a cache-like structure that may be referred to without network communication. Misses within this cache structure cause a refreshing of the cache from the global resource locator and an updating of a learning relation table that further improves predictions in the future. Historical successes in bidding are stored at the cache structure to further aid in selecting likely bid recipients.

Abstract: In an autonomous cooperative control system a job description of job steps is drafted in a scripting language and compared to corresponding machine steps associated with each independently controlled machine also drafted in the same scripting language for simple comparison and generation of sub-bids for further bidding. The machine steps generated for each ACU provides a vocabulary for the job description language which may be further simplified by hiding lower level machine steps in the ACUs to be activated only upon a matching with a job step. The ACUs may select between connected and unconnected messaging based on historical communication patterns to reduce network traffic.

Abstract: A controller configured to operate as at least one agent, a method of configuring a controller for operation as part of a multi-agent distributed control system, and a configuration device for so configuring a controller, are disclosed. The controller includes at least one processing device and at least one storage medium that is in communication with the at least one processing device. The at least one storage medium stores a plurality of program portions that are executed by the at least one processing device, and the plurality of program portions includes first, second and third program portions. The first program portion is capable of generating first signals that are commands to be provided to a controlled device, the second program portion is capable of governing standard agent-type functionality, and the third program portion is capable of governing application-specific agent-type functionality.

Abstract: A transmission schedule is overlaid on the Ethernet protocol to allow use of this readily available high speed protocol for transmission of I/O data communicated in an industrial control environment and requiring a high degree of determinism. Scheduling improves load leveling and bandwidth utilization and by producing a more consistent delay may be teamed with time synchronization to produce more accurate clock synchronization.

Abstract: A method of precisely synchronizing clocks held in separate nodes on a communication network is provided that adjusts clock frequency based on a measure of relative clock rates and absolute clock offsets. In one embodiment, clock convergence is obtained with one synchronization session.

Abstract: A distributed control system and methods of operating such a control system are disclosed. In one embodiment, the distributed control system is operated in a manner in which interrupts are at least temporarily inhibited from being processed to avoid excessive delays in the processing of non-interrupt tasks. In another embodiment, the distributed control system is operated in a manner in which tasks are queued based upon relative timing constraints that they have been assigned. In a further embodiment, application programs that are executed on the distributed control system are operated in accordance with high-level and/or low-level requirements allocated to resources of the distributed control system.