基于CAN总线的某通信系统应用层协议的设计与实现

以CAN2.0A为基础,通过安装在PC机上的内置SJA1000 CAN(控制器局域网)控制器的CAN总线通信接口卡实现CAN总线与PC机的通信,通过CAN总线通信接口卡函数实现自己制定的应用层协议。该协议根据某通信系统需要及CAN滤波方式,确定了信息ID(标识符)的分配,定义了报文传输格式。文中分析了单双滤波对本系统报文接收的影响,验证了本协议的可行性及合理性,最后给出本协议多帧数据传输的编程实现。     

基于S3C2440的CAN总线接口设计与驱动实现

介绍了一种采用CAN总线控制器MCP2510对嵌入式处理器S3C2440进行CAN接口扩展的设计方案,并给出了详细的硬件电路,同时在研究分析了Linux系统下CAN设备驱动程序的开发流程的基础上,结合CAN总线技术规范和MCP2510的特点设计了相关的数据结构和软件代码,从而实现了对CAN设备的驱动。     

CAN智能节点的设计

CAN总线是一种流行的实时性现场总线 ,文中提出了一种基于MSP430单片机 ,并以MCP2510为CAN控制器的智能节点设计方案 ,该方案利用MSP430通过标准SPI接口可实现对MCP2510的控制 ,并能够完全实现CAN总线规范。     

嵌入式ARM9200与MCP2510的通信

介绍了ATMEL公司AT91ARM9200和美国微芯科技公司的CAN(控制器局域网)控制器MCP2510芯片的结构和功能,重点介绍AT91ARM9200与MCP2510的SPI(串行外设接口)连接,阐述AT91ARM9200和MCP2510的初始化过程以及简单的通信过程。     

CAN控制器MCP2510及其应用

MCP2510是MT公司生产的一种带SPI接口的CAN控制器,主要用于简化CAN接口的应用设计。文中介绍了MCP2510的特点、结构和基本工作原理,给出了其应用接口电路及SPI接口协议的软件实现方法。     

一种CAN总线智能节点的设计

介绍基于MCP2510的CAN总线智能节点的硬件和软件设计.     

基于双层CAN总线的声纳数据通信系统设计

针对船舶声纳信号采集区域广、传输数据量大的问题,设计了一种基于双层CAN总线的声纳数据通信系统。系统以PIC18F4580单片机作为中间控制器,利用自身集成的CAN控制器与各采集单元节点进行通信,通过外部扩展CAN控制器MCP2510与上位机进行通信,以双CAN总线接口实现双层、多区域数据通信。通过实验检测,无数据传送出错和数据丢失现象,性能稳定可靠。     

基于SPI的CAN总线控制器与MCS-51单片机的接口设计

本文提出了一种基于SPI的cAN总线控制器与MCS-51单片机接口的智能节点设计方案.单片机通过模拟SPI接口实现对MCP2510的控制,从而实现CAN总线的通信.     

基于AT91RM9200的CAN智能节点设计

在此提出一种基于AT91RM9200处理器,并以MCP2510为CAN控制器的智能节点设计方案。首先描述CAN智能节点硬件的设计原理并给出了选用的主要芯片的型号;接着详细描述CAN智能节点软件设计流程;最后说明CAN智能节点软、硬件的调试方法。目前已完成CAN智能节点硬件和软件的设计及调试,并成功移植到VxWorks5．5操作系统上运行,证明了该设计方案正确可行。     

CAN总线在智能仪表中的应用研究

本文详细介绍了仪表的CAN总线通信的实现过程,对MSP430FG4618单片机、CAN控制器SJA1000、以及CAN收发器82C250进行了探究,并以它为处理器进行硬件设计,使CAN总线的通讯更加直观。本文在分析论述了现场总线技术的有关性能特点及CAN协议规范后,完成了CAN通信卡的电路设计;在软件上实现了PC机通过CAN通信卡对CAN现场总线仪表实现远程管理等功能。     

V5.x协议测试系统

首先概述了 V5 .x接口的功能及 V5 .x协议的结构 ,在此基础上 ,详细阐述了在 PC机上实现 V5 TS (V5 .x协议测试系统 )的测试原理及方法。最后 ,通过一个测试举例 ,描述协议消息的传输过程。     

电子束时间展宽皮秒分幅相机

研制了基于电子束时间展宽技术和微通道板（microchannel plate,MCP）选通技术的时间展宽分幅相机。相机有三条厚度80 nm、宽度8 mm的微带阴极,阴极上加载斜率为2.1 V/ps的高压斜坡脉冲,使得先发射的电子较后面的电子速度快,经过50 cm的漂移区后,电子束产生时间展宽,从而提高相机时间分辨率。阴极和MCP均加载了脉冲电压,因此,需要精确同步光脉冲、阴极脉冲和MCP选通脉冲,分析了完整的同步过程。当阴极仅加直流电压,无电子束时间展宽时,获得相机的时间分辨率为78 ps。当阴极加载高压斜坡脉冲时,电子束时间展宽技术将系统的时间分辨率提高至12 ps。改变延时,将光脉冲分别同步在斜坡脉冲不同位置,获得了时间分辨率与同步位置的关系。     

DFEMD: Delay Tolerant Fast Emergency Message Dissemination Routing Protocol

In vehicular ad-hoc network, vehicles are move very speedy thus their topology is changing frequently and intermittent connectivity occur often. The intermittent connectivity network (delay and disruption-tolerant network) resulting is end to end path is absent. In this intermittent network connectivity areas, during emergency event occurs, emergency rescue message (Example: Fire, Accident, etc.,) are sent to a rescue team is most necessary. Due to these constraints, general ad hoc protocol approaches is not suitable and, as a result, alternative protocol must be deliberated. This leads to the make a specific protocol mechanisms able to deliver both fast and trustworthiness in-order delivery emergency message needed. Thus we introduce the DFEMDR protocol, it follow the vehicular delay tolerant network (VDTN) common technique store carry-forward method and message replicas. This paper describes an efficient Delay tolerant Fast Emergency Message Dissemination Routing Protocol, called DFEMD routing protocol. This protocol enables in VDTN, the source node broadcast an emergency message to all available node in its communication range. The source node allocates a message replicas and message time to live to the neighbour nodes (forwarded node) based on that node has credence value. Credence value is calculated to all nodes based on two values; the first value is visited level estimation, it is calculated based on the number of nodes previously visited by the node. The second value is Destination Reaches Level Estimation (DLE); it is calculated based on the number of times the node successfully delivered the message to the destination. Finally, each node credence value is calculated, from this visited level and destination reaches level estimation values. Finally, the trust authority received emergency messages and evaluate the trustworthiness of message based on message reputation value or message confidence value.

     

可视电话系统中多媒体通信控制协议H.245的实现

介绍了Ｈ．３２４可视电话系统中多媒体通信控制协议Ｈ．２４５的原理及其在ＰＣ机Ｗｉｎｄｏｗｓ９５环境下的软件实现,讨论了抽象语法符呈ＡＳＮ．１和打包编码原理（ＰＥＲ）。Ｈ．２４５主要包括两部分：一是信令的组成和结构模式,另一是通信规程的具体过程。前一部分利用ＡＳＮ．１和ＰＥＲ对信令进行描述和编码,文中采用一种编译器把信令从ＡＳＮ．１格式转化为Ｃ语言数据结构格式,然后进行处理,后一部分采用有限状态机的     

Selective parsing to enhance SIP performance

The session initiation protocol (SIP) is used as the signaling protocol in the IP multimedia subsystem (IMS) and the signaling is becoming computing intensive comparing to the current telecommunication network. The SIP is a text-based protocol with characteristics of unordered and verbose headers, variable-size message, and case-insensitive keyword. It imposes challenges for an efficient message processing. The property of SIP elements being able to process SIP messages quickly is critical for the performance of IMS networks. This article investigates the performance of SIP message processed in SIP servers, mainly focusing on improving message parsing by introducing a method named selective parsing for SIP message (SP4SIP). By modeling and analyzing a SIP server with a tandem Jackson network, it is concluded that parsing messages is the bottleneck of a SIP server performance, i.e., it is the most processing intensive activity in the system. To validate the approach, it has been implemented in a high-performance SIP server in the authors' lab. The results show that selective parsing for SIP message can indeed reduce processing time.     

Design on enterprise service bus message conversion protocol based on XSLT

Enterprise service bus (ESB) plays the part as intermediate hubs in enterprise service integration frameworks, and it is to implement the communications of shared contents in different systems. These contents are heterogeneous and message conversion protocols make rule of the transformation among them. This article studies about designing on enterprise service bus message conversion protocol based on extensible stylesheet language transformations (XSLT). It includes three parts of design of the ESB: message conversion frame, message conversion optimization and heterogeneous message integration. The first part introduces the process of service request and response using simple object access protocol (SOAP) in ESB and makes analysis about XSLT file elements. The second part sets up multiple-request message pattern by XSLT processor and ESB pre-defined request message content format based on Schema. The third part optimizes intelligent message conversion in ESB by automatic Schema mapping rule. All the functions help to develop the intelligent message conversion in ESB and improve the efficiency of the conversion.