Implementing reliable communication controllers using the Oberon environment
Damir Bursic, Stephan Grimm, Hans Dermot Doran · Zürcher Hochschule für Angewandte Wissenschaften digital collection (Zurich University of Applied Sciences) · 2009
Real-Time Ethernet (RTE) technology has established itself as a mainstream technology since its introduction to the market in 2002 and an ecosystem of communication component suppliers, both hardware and software, has evolved. With the evolution of the market has come an increased requirement for high-reliability, high-availability and safety-orientated solutions. RTE protocols are an order of magnitude more complex compared to earlier field-bus protocols. The nature of bandwidth/response-time requirements sometimes demands multi-processor or communication-controller/processor architectures and an RTE protocol may utilize 3+ sub-protocols. Protocol specifications are sometimes either lacking in detail or open to wildly differing interpretations. This complexity increases the maintenance effort for protocol stacks hence communication modules may be subject to frequent firmware and software updates. This presentation describes an Oberon implementation of the Ethernet POWERLINK protocol suitable for use on communication modules. Oberon, a strongly typed object orientated language integrated with a run-time environment, is suitable for manual inspection making it interesting for safety certification. The presentation concisely describes the advantages of Oberon and critically examines the tool-chain. The presentation then describes typical critical points in stack architectures and specifications before describing a restrictive implementation of POWERLINK in Oberon so that availability on operation is maximized. The presentation then describes measurement results and compares with results obtainable in a typical POWERLINK stack written in ‘C’ before drawing appropriate conclusions.