【作者】 贾超；

【导师】 陈在平；

【作者基本信息】 天津理工大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 DeviceNet作为现场总线的国际标准之一,已日益成为人们的关注焦点。因此,开展基于DeviceNet从节点开发技术的研究就显得十分紧迫和必要。本文在充分研究DeviceNet协议规范的基础上,设计了一个采用CAN独立控制器SJA1000实现的DeviceNet现场总线通信节点。该节点在遵循预定义主从连接组相关规范的基础上,可满足基于开关量、模拟量等基本数据类型的输入输出功能,并同时支持轮询和位选通两种I/O数据的触发方式。论文首先介绍了DeviceNet的国内外研究进展、本文的研究内容与意义,然后具体说明了DeviceNet的协议规范,并针对所支持的两种主要数据触发方式——轮询和位选通的工作原理进行了详细的介绍。在此基础上,对通信节点进行了硬件设计。由于CAN独立控制器具有可移植性强,功能强大等特点,本文首先对SJA1000控制器及相关器件作了简要说明,然后采用SJA1000控制器实现DeviceNet通信节点的硬件开发,给出了从节点的硬件电路,并通过了调试。DeviceNet从节点的软件设计采用C51语言来实现。为了使程序结构更加清晰,以及方便程序的调试,本文以基于对象化的编程方法编写了应用层程序。该程序可实现对SJA1000及相关参数的初始化,CAN报文的收发等基本功能,并按照DeviceNet协议规范实现重复MAC ID检测、配置连接实例、显示报文的收发等功能,且考虑了在轮询和位选通两种数据触发方式下的通信要求,给出了具体的程序代码。为了验证所开发节点的功能,本文最后搭建了DeviceNet从节点测试平台,并对所开发节点进行了测试,通过对实验数据的分析,证明从节点行为完全符合DeviceNet规范要求,实现了多种数据触发方式下智能从节点的通信功能。更多还原

【Abstract】 As one of the international standards of fieldbus,DeviceNet has become focus of attention increasingly.Therefore,do some research on development of slave node based on DeviceNet is very pressing and necessary.After research the protocol specification of DeviceNet,this paper designs a DeviceNet fieldbus communication node which used the SJA1000,a type of separate CAN controller.On the basis of following the predefined master/slave connection set specification,the node can meet the input and output functions with either digital or analogue data type,and support both poll and bit-strobe I/O data trigger modes.First , this paper describes the research progress of devicenet home and abroad、content and significance of this paper,and specified the protocol specification of DeviceNet.Then give the detailed working principle of poll and bit-strobe which are the primary data trigger modes.After then,it designs the hardware circuit of commnication node.For the good portability and powerful functions of separate CAN controller,this paper gives a brief description of SJA1000 and other components firstly,then uses the SJA1000 CAN controller to complete the hardware development of DeviceNet communication node,also gives the detailed hardware circuit,and gets through the debugging.The software design of DeviceNet slave node is realized by C51 language.For more clear program structure and simplifying the debugging process,this paper edit the program of application layer based on objectification programming method.The program can realize the elementary functions such as initialization of SJA1000 and correlative parameters ,also the transceiving of CAN message,etc.Then,it can realize the duplicate MAC ID detection、configuration of connection instances、transceiving of explicit message,etc.After that,it considers the communication demand of both poll and bit-strobe modes,and gives the detailed program code.For testing the function of the slve node which this paper have developed,it builds a test platform for DeviceNet slave node,and also tests the developed node.By analyzing the experimental data in detail,it has proved that the node can act according the demand of DeviceNet specifications completely and realize the communication function of intelligent slave node in different data trigger modes.更多还原