摘要
在介绍和分析Profibus协议的FDL工作机理的基础上,对Profibus-DP的MAC层协议进行了修改,改变原有的优先级设置方式和调度策略,使它更适应于特定的实时性与可靠性要求很高的工业现场的控制系统。并对新MAC层协议基于排队理论进行了建模,由动态时间限制服务策略推出了一个响应等待时间公式。通过有关计算响应等待时间与TTR关系的例子,表明了模型的可用性,并证明了它是研究MAC层协议的有效工具。
This paper made an introduction and an analysis on the working mechanism of the FDL the Profibus protocol, then the MAC layer protocol of the Profibus-DP was modified the original priority setting and scheduling strategy were changed , so that it can be better used in some specific distributed control systems. Besides, based on the queuing theory, this paper also made a model of the new MAC layer protocol, and a response waiting time formula was inferred from the dynamic time limited service strategy. Finally, through the calculation of an example, this paper illustrated the relation between 3TR and response waiting time.
出处
《重庆理工大学学报（自然科学）》
CAS
2012年第9期69-74,共6页
Journal of Chongqing University of Technology：Natural Science
基金
国家科技重大专项(2009ZX04005-011)
关键词
实时性
调度策略
排队论
响应等待时间
real-time
scheduling strategy
queuing theory
response waiting time
