Issue No.12 - December (2009 vol.58)
Li Hsien Yoong , The University of Auckland, Auckland
Partha S. Roop , The University of Auckland, Auckland
Valeriy Vyatkin , The University of Auckland, Auckland
Zoran Salcic , The University of Auckland, Auckland
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2009.128
IEC 61499 has been endorsed as the standard for modeling and implementing distributed industrial process measurement and control systems. The standard prescribes the use of function blocks for designing systems in a component-oriented approach. The execution model of a basic function block and the manner for event/data connections between blocks are described therein. Unfortunately, the standard does not provide exhaustive specifications for function block execution. Consequently, multiple standard-compliant implementations exhibiting different behaviors are possible. This not only defeats the purpose of having a standard but also makes verification of function block systems difficult. To overcome this, we propose synchronous semantics for function blocks and show its feasibility by translating function blocks into a subset of Esterel, a well-known synchronous language. The proposed semantics avoids causal cycles common in Esterel and is proved to be reactive and deterministic under any composition. Moreover, verification techniques developed for synchronous systems can now be applied to function blocks.
Compilation, Esterel, function blocks, IEC 61499, synchronous semantics.
Li Hsien Yoong, Partha S. Roop, Valeriy Vyatkin, Zoran Salcic, "A Synchronous Approach for IEC 61499 Function Block Implementation", IEEE Transactions on Computers, vol.58, no. 12, pp. 1599-1614, December 2009, doi:10.1109/TC.2009.128