退避算法中随机数范围对工业Ethernet实时性的影响  

Influences of the Range of Random Number in Binary Exponential Back-off Algorithm on Rea-time Property of Industrial Ethernet

作　　者：姜庆标[1] 

机构地区：[1]南京工程学院自动化系,江苏南京210013

出　　处：《南京工程学院学报（自然科学版）》2006年第1期19-22,共4页Journal of Nanjing Institute of Technology(Natural Science Edition)

基　　金：南京工程学院科研基金资助项目(KXJ04051)

摘　　要：明确地定义了冲突概率系数、最小可能概率和微小概率,用最大可能冲突次数这一概念,阐明了网络最大延时的计算方法.着重论述了退避算法中的随机数R的取值范围会影响以太网的最大延时,合理地选取Rm ax值,能够使工业Ethernet具有更好的实时性,完全能够满足现场控制的实时性要求.The paper defines the collision probability coefficient, the minimum feasible probability and the tiny probability. The method of calculating the maximum delay of a network is clarified with the concept of the maximum feasible collision time. The author points out that the maximum delay of Ethernet is influenced by the range of the random number in Binary Exponential Back-off Algorithm, and that choosing a proper value of the maximum random number secures the industrial Ethernet a good real-time property, thus satisfying the demands of process control.

关 键 词：最大延时 最小可能概率 退避算法 最大可能冲突次数 

分 类 号：TP393.01[自动化与计算机技术—计算机应用技术]