A Framework for Establishing Performance Guarantees in Industrial Automation Networks

摘要

In this paper we investigate the application of Network Calculus for industrial automation networks to obtain performance bounds (latency, jitter and backlog). In our previous work we identified the modeling of industrial networks as the most challenging aspect since in industry most users do not have detailed knowledge about the traffic load caused by applications. However, exactly this knowledge is indispensable when it comes to modeling the corresponding arrival curves. Thus, we suggest the use of generalized traffic profiles, which are provided by the engineering tool. During the engineering process, the user has to specialize these profiles to meet the application configurations. The engineering tool derives the corresponding arrival curves from the specialized profiles and calculates the performance bounds using Network Calculus. To guarantee that the calculated performance bounds are kept during the runtime of the industrial automation, we must ensure that the real traffic flows do not exceed their engineered arrival curves. We therefore propose the use of shapers at the edge of the network domain. The shaper configurations can be automatically derived from the engineered arrival curves of the flows.