Reservation-Based Data Flow Scheduling in Distributed Control Applications

Remote process control and supervision applications developed over the Internet require special communication models and techniques, which can guarantee the real-time and safety restrictions inherent to automation systems. This paper presents a communication model based on dataflow analysis and bandwidth reservation that offers a good control over the transmission time of critical data. As part of the model, an analytical method is proposed that allows a-priory evaluation of the required minimum bandwidth necessary to assure the fulfillment of real-time transmission restrictions. The model is based on the QoS facilities offered by the IPv6 protocol.