Abstract: Aspects of the invention support direct communication between a low-level device and a programmable controller over an automation bus in an industrial automation system for controlling and monitoring an industrial process. A leaf node device may include a low-level device. The leaf node device communicates directly with the programmable controller at the network layer, e.g., Internet Protocol (IP) based on an IP address contained in a signal so that the programmable controller may control the low-level device or receive status information about the low-level device. The industrial automation system may support a plurality of leaf node devices, which may be associated with different automation buses having different communication media. Signals between the programmable controller and the leaf node device may be directed with or without a switching element.

Abstract: A network comprises a plurality of network devices, including a first network device coupled to a second network device and a third network in a daisy chain topology configuration. The first network device has a first device port connected to a first network port and a second device port connected to a second network port. A bypass switch is coupled to the first network device and creates a bypass path when the first network device is inoperable. The bypass switch is coupled to a processor in the first network device. The processor has a control function for closing the bypass path when the first network device is inoperable and for opening the bypass path when the first network device is operable. The bypass switch connects the first network port to the second network port when the device is inoperable.

Abstract: A method for performing rate policing and re-marking in a packet switched communications network that can be used to enforce and/or monitor Class of Services (CoS) contracts including terms for single or multiple classes of service. A switching system configured as an ingress node on the network includes a network switch and rate policing and re-marking logic. The switch receives a data packet transmitted on the network, extracts information from at least one header field of the packet including a CoS parameter, a primary flow ID established for the packet, and a packet byte count, and provides the extracted information to the rate policing/re-marking logic. Next, the rate policing/re-marking logic performs flow record and token bucket processing on the primary packet flow to determine whether the packets of the primary flow conform to the bandwidth requirements specified in the CoS contract.

Abstract: A method for performing rate policing and re-marking in a packet switched communications network that can be used to enforce and/or monitor Class of Services (CoS) contracts including terms for single or multiple classes of service. A switching system configured as an ingress node on the network includes a network switch and rate policing and re-marking logic. The switch receives a data packet transmitted on the network, extracts information from at least one header field of the packet including a CoS parameter, a primary flow ID established for the packet, and a packet byte count, and provides the extracted information to the rate policing/re-marking logic. Next, the rate policing/re-marking logic performs flow record and token bucket processing on the primary packet flow to determine whether the packets of the primary flow conform to the bandwidth requirements specified in the CoS contract.