摘要:

为了满足系统各个任务对实时性的要求,需要实现各个任务的并行处理。针对VxWorks操作系统的多任务调度机制和任务通信方式进行了分析;采用基于时间片轮转调度实现多任务程序设计,可以动态改变各个任务期望运行的时间片;对各种通信方式和实现方法进行了比对,并给出了优化方案。上述设计方法实时性强,可靠性高,系统可扩展性良好,能够很好地满足工程需要。

下载地址

Files:
Date 2018-10-16
File Size 835.17 KB
Download 514

In order to meet the real-time demands of the multi-task of the system,the parallel processing for all kinds of tasks was required.Multi-task scheduling and task communication mechanism about VxWoks operating system were analyzed.The design of rotating schedule based on time slice was put in use on the multi-task programming,as well as,the time slice of the expectations of each task running could be dynamically changed.At the same time,most of the communication means and methods were compared,and the better optimization was given.The method could be satisfied the engineering requirments with good performance on real time characteristics,high reliability,and good expansibility.

摘要:

本文以PC104工控机和数据采集模块为硬件平台,介绍了多任务实时操作系统VxWorks,研究了基于Vxworks的数据采集卡初始化,任务初始化.数据采集、数据存储等技术,设计了基于Vxworks实时操作系统的数据采集存储装置。该装置成功应用于海洋环境测量,且能长期稳定可靠运行。

下载地址

Date 2018-10-16
File Size 441.13 KB
Download 498

Abstract:

In order to improve the stability and reliability of under water automatic data acquisition storage system, the device of system is constituted of pc104 bus a/d acquisition module and embedded computer.We realized tasks communication, data acquisition, data acquisition storage, has completed data acquisition storage, device design debugging based on real-time multitasking operating system for data acquisition card initialization, task initialization. This device has been applied for marine environmental measuring successfully and could be used stably, long term and reliably.

Keywords:

VxWorks; multitask; initialization;

近二十年,在技术不断发展的前提下,世界互联网得到飞速的发展,使得我们几乎能在世界上任何角落连接互联网。与此同时,我国的互联网也在不断拓展。而实时通信技术也因为互联网的普及而得到了广泛的应用,其中,VoIP 技术是一项新兴的实时通信技术,通过在互联网上传输话音数据,使人们能够更加便捷的进行语音通信。

在网络广泛应用之前,人们大多使用电路交换方式的PSTN。在多年的积累下,PSTN 网络遍布全球,并且在今后长时间内PSTN 会继续在通信方式上占据很大的比例。在这个实际情况下,研究并开发一种连接PSTN 和IP 网络的设备就成为了一种必然。

论文基于以上观点,提出一种网关设备的设计方案,其能够有效沟通PSTN网络和IP 网络,使两种网络用户能够可靠的进行语音通信。论文对网关设备进行了硬件、软件设计。其中硬件部分包含有微处理器、话音AD/DA 转换芯片、话音编解码芯片等。软件系统设计采用模块化的方案,主要包含话音处理模块、信令转换模块和以太网处理模块等。软件系统的设计与实现是本文工作研究的重点。

软件系统以具有强大功能的IXP425 处理器芯片为核心,运用嵌入式VxWorks作为底层操作系统,开发内容包括语音编码和解码、信令转换的设计和实现、以太网传输实现等。经过开发和设计,该网关设备实现了以下功能:模拟语音的采集、编码及其逆过程;话音编码类型的转换;PSTN 侧与IP 侧信令的转换;信令、语音数据在网络上的传输。

最后根据设计目标对网关设备进行了性能测试。测试结果验证了本文提出的基于VxWorks 系统的VoIP 网关设计方案和开发过程的正确性。

下载地址

Date 2018-10-12
File Size 1.6 MB
Download 446

摘要:

通信声纳的小型化以及通信任务的实时处理是水声通信发展的趋势,特别是在军事水声通信中。本文介绍了在PC104平台下,基于嵌入式实时操作系统VxWorks的水声扩频通信系统的实现。它能够实时地协调数据采集、发射信号、对接收信号进行处理、串口通信多个任务;且整个系统规模甚小。

下载地址

Date 2018-10-16
File Size 2.17 MB
Download 413

摘要:

由于VxWorks平台在电信领域的巨大市场和SCTP协议在IP网传输电信业务数据的优异性能,研究基于VxWorks平台的SCTP协议具有重要的意义。通过对SCTP协议基本概念和高级特性的简单介绍及它与传统传输协议主要区别的简单对比,凸显了SCTP协议的优越性能。提出了SCTP协议的软件设计方案。重点设计了协议的初始化机制、数据发送机制和数据接收机制,重点优化了协议的实时处理能力。通过工程实践表明,即使在不稳定网络等恶劣条件下,SCTP协议能够更高效,更可靠地完成数据的传输。证明了SCTP协议作为下一代传输协议具有广阔的前景。

下载地址

Date 2018-10-12
File Size 901.59 KB
Download 544

VxWorks platform has a huge market in the field of telecommunications and the SCTP protocol exhibits outstanding performance in IP network transmission of telecommunication traffic,so it is very important to research SCTP protocol based on VxWorks platform.This paper introduces the basic concept and advanced features of the SCTP protocol,and makes a brief contrast with the traditional transfer protocol,thus showing the superior performance of the SCTP protocol.SCTP protocol software design is also proposed with focus on the design of the protocol initialization mechanism,data transmission mechanism and the data receiving system,this optimizes real-time processing capability of the protocol especially.The engineering application shows that even in unstable networks and other adverse conditions,SCTP protocol can be more efficient and more reliable in data transmission,and SCTP protocol has broad prospects as a next-generation transport protocol.