3CHEN Ji-ming, WANG Zhi, SUN You-xian. A basic study on algorithm of real-time schedule table for fieldbus [A]. Proceedings of the 4th World Congress on Intelligent Control and Automation [C]. Shanghai: Press of ECUST, 2002. 1760--1763.
4TOVAR E. Supporting real-time communications with standard factory-floor networks [D]. Porto: University of Porto, 1999. 98--99.