[信息与通信]基于CAN的多生产线产品自动统计系统设计.doc

基于CAN的多生产线产品自动统计系统设计 摘 要 现场总线是自动化领域的计算机网络。CAN总线作为目前最有前途的现场总线之一，以其实时性好、可靠性高、性价比突出的优点，已经逐渐成为当今自动化领域发展的热点之一，被广泛应用于工业控制领域。本文通过对CAN总线网络的构成和协议的分析，给出了基于CAN总线多生产线自动统计系统的总体设计方案，完成的主要工作如下： 基于AT89C51和SJA1000设计了多生产线产品自动统计系统节点。设计了系统节点的硬件电路及应用程序，包括CAN控制器SJA1000的初始化、信息发送及中断接收等。制定了面向应用层的CAN总线网络通讯协议，实现了CAN网络中各节点之间的通信。 CAN总线；；。Design of Products Automatic Statistical System for Multiple Product Lines Based on CAN Abstract:Field bus is a kind of computer network in the automatization field.As one of the most promoting field bus,CAN bus has become one of the developmental hotspot in automatization field gradually and been widely used in the industry control domain because of its many advantages,such as outstanding real time ability,high reliability and low price. This paper proposes the whole design scheme of the many production lines products automatic statistical system based on CAN bus through the composing of CAN field bus network and communicating protocol.The main tasks finished are as follows. The many production lines products automatic statistical system node is designed based on AT89C51 and SJA1000.The hardware circuit and the software of this node are designed,including the initialization of CAN controller SJA1000,the transmission and the interrrupt reception of the message and so on. a new protocol for user layer communication which is presented. The communication between all nodes of the CAN network are all realized. Key words:CAN bus; Photoelectric sensor; Network Protocol. 目录 第一章 前 言 5 1.1 现场总线在工业自动化领域的应用 5 1.1.1 现场总线概述 5 1.1.2 现场总线在工业自动化领域应用实例 7 1.2论文研究的意义 9 1.3论文的主要研究内容 10 第二章 CAN总线概述 11 2.1 CAN 的应用现状 11 2.2 CAN 的技术特征 12 2.2.1 CAN总线编码 12 2.2.2 CAN总线仲裁方式 13 2.2.3 CAN总线分层结构 14 2.3 CAN总线工作原理及其可靠性 15 2.4 CAN总线节点结构 18 第三章 系统硬件设计 19 3.1 系统结构 19 3.2 生产线CAN节点构成 19 3.2.1计数器硬件设计 20 3.2.2 CAN通讯接口设计 21 3.3 上位机CAN节点构成 23 第四章 系统软件设计 25 4.1系统软件流程 25 4.2 CAN总线网络通信协议制定 25 4.2.1 CAN2.0B协议规范 26 4.2.2 自定通讯协议 27 4.3 CAN节点初始化程序 30 4.4节点报文收发程序 32 4.4.1 SJAI000的信息发送 32 4.4.2 SJA1000的信息接收 34