中文摘要：

针对PROFIBUS实时可调度性分析的现有结果仅考虑任务截至期而没有考虑次序关系的缺陷，建立了新的基于图论综合分析方法。采用图论描述次序关系和构造合理的令牌环，并根据运行结果动态调整令牌环顺序、减少系统的总延迟。通过解析分析和实例验证了所提出的新方法。

英文摘要：

As one of European standard（EN5070）, PROFIBUS is based on a simplified TTP（time-triggered protocol ）and is a well welcome fieldbus to guarantee real-time communication for industrial application. The deficiency of present shedulability on token rotation time, never related to the sequence of token rotation that controls the slots for message response in master stations. Based on the character of industrial application, a holistic schedulability using graph theory is given, and a method is described to improve the temporal function of PROFIBUS.