文档介绍：LonWorks总线实时通信协议的研究
张玉萍,佟为明,李辰
(哈尔滨工业大学电气工程与自动化学院哈尔滨 150001)
摘要:从LonWorks总线的介质访问机制入手,本着冲突避免和冲突解决两个原则,论证了LonTalk协议在实时性方面存在的问题。对LonTalk协议的MAC仲裁机制进行了改进,提出了一种新的实时通信协议,解决了因较高优先级节点交替占用总线而使较低优先级节点长期得不到总线使用权的问题。实验结果表明,与原协议相比,新的实时通信协议在网络节点数大于10时,%以上,网络有效利用率提高了100%。新的实时通信协议在实时性、确定性等方面均优于原协议。
关键词:LonWorks总线;实时性;LonTalk协议;MAC机制
中图分类号:TP393 文献标识码:A 国家标准学科分类代码:
Study on the real munication protocol of LonWorks bus
Zhang Yuping, Tong Weiming, Li Chen
(School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China)
Abstract:Starting from the media access control mechanism of the LonWorks bus and based on the principle of collision avoidance and collision resolution, the problem of real time property in the LonTalk protocol is proved, and the MAC arbitration mechanism of LonTalk protocol is improved. A new real munication protocol is proposed, which resolves the problem that low priority nodes can not obtain bus access authority over a long period of time, because the bus is occupied alternatively by high priority nodes. Experiments show pared with the previous protocol, when the number work nodes are more than 10, the new real munication protocol reduces the maximum delay time of message transmission at least by % and work utilization efficiency is enhanced by 100%. The new real munication protocol is superior to th