A model for fault-tolerant networked control system using TTP/C communication

Safety-critical aerospace functions are generally required to have failure rates less than 10/sup -9/ per hour (FAA, 1988) and an architecture that supports several such functions is required to have failure rates less than 10/sup -10/ per hour. Although the requirement for an individual automobile may be more relaxed, similar requirements apply for automobiles in general (Rushby, 2001), because of their large number as compared to aircraft. Consumer-grade electronics have failure rates that are orders of magnitude worse than this. Hence, redundancy to improve failure rates and fault tolerance to prevent faults from propagating both are essential elements of a safety critical networked control system (NCS). TTP/C is a member of the time-triggered protocol (TTP) family that satisfies Society of Automotive Engineers Class C requirements for hard real-time fault-tolerant communication. A model is presented for a fault-tolerant NCS using TTP/C communication. Appropriate features of TTP/C are incorporated in the model. A simulation is presented for the electric power steering node with switching controller, which makes the node tolerant to the parameter faults column.     

Architecture of a comprehensive radiologic imaging network

An emerging concept in picture archiving and communication systems (PACS) is the PACS infrastructure. The critical components in this infrastructure are communication systems, cluster controller, database integration, fault-tolerant design, and systems integration software. The architecture of a comprehensive communication system within this infrastructure, which will support a digital-based radiology operation, is described. This communication network consists of a real-time analog video and digital components. The video network utilizes broadband and fiber-optic communication technologies. The digital communication is based on a three-tiered network integrating Ethernet, FDDI, and Ultranet technologies. The digital network uses the standard TCP/IP protocol and has a fault-tolerant design. Both components have been in clinical operation since the summer of 1991     

文字电话的液晶显示与实现

文中实现了文字电话通信前等待界面和通信中信息的液晶显示。使用Microchip公司生产的dsPIC33F数字信号控制器与16位开发板,以MPLAB为开发平台,使用C语言编程并通过C30进行编译完成对数字信号控制器的控制,从而实现控制器驱动液晶显示模块实现显示。利用点阵型液晶显示模块TSB1G7000的命令字实现显示界面的小图标设计和滚屏设计,并且实现了通信过程中双方通信数据的显示。实践表明,使用dsPIC33F数字信号控制器与液晶显示模块构成的显示系统可以满足文字电话的显示要求。     

HCMS-2903数字显示器及应用系统设计

HCMS-2903是一种高性能、易于使用的CMOS数字字符点阵显示的发光二极管显示器(LED)芯片.文中在简要介绍HCMS-2903结构特点、通信协议的基础上,介绍了利用HCMS-2903作为显示器、单片机AT89C52作为控制器、计算机作为数据源而实现数字画面的显示、切换和控制的原理,以及硬件结构和软件设计等.该设计已被用于工程实践,获得了满意的效果.     

基于ARM的某智能弹药无线通信模块的设计

为了适应某弹药项目中各个节点在高速飞行的情况下,硬件上必须轻捷稳定,软件上必须完全支持该模块利用某复杂协议进行可靠通信和无线数据传输的要求,自主设计了以S3C2440ARM为主控制器和以嵌入式linux2．6为操作系统的无线通信模块,本文以简明扼要的语言介绍了该无线通信模块从硬件设计到到bootloader移植,linux内核移植,根文件系统制作,以及设备驱动程序开发过程中每个关键技术的设计步骤和测试结果。     

Peripheral board controller for digital exchange systems

The controller implements a redundant PCM highway port and a 4-Mb serial communication link. Typical features are variable time slot assignment for up to 16 subscribers, processing of status signaling and feature control data, and high level support of the HDLC (high-level data link control) communications protocol. The circuit represents an innovative step in the development of modern subscriber boards in digital switching systems, particularly in the area of fully digital voice and data transmission capability. The circuit is realized in a 3.5-/spl mu/m NMOS process and contains more than 22000 transistors on a 7.24/spl times/5.24 mm die area.     

Design and Implementation of Embedded Transmission Control Protocol/Internet Protocol Network Based on System-on-programmable Chip

A scheme of transmission control protocol/Internet protocol（TCP/IP） network system based on system-on-programmable chip（SOPC） is proposed for the embedded network communication. In this system, Nios processor, Ethernet controller and other peripheral logic circuits are all integrated on a Stratix Ⅱ field programmable gate array （FPGA） chip by using SOPC builder design software. And the network communication is realized by transplanting MicroC/OS Ⅱ （uC/OS Ⅱ ） operation system and light weight Internet protocol（LwIP）. The design idea, key points and the structures of both software and hardware of the system are presented and ran with a telecommunication example. The experiment shows that the embedded TCP/IP network system has high reliability and real-time performance.     

基于Visual C++的传感器稳定性测试系统设计与实现

本文基于传感器稳定性测试中存在的一些效率低等问题,开发并设计出一套Visual C++的系统.在计算机的主控器上指令编程IO数字量输出卡,完成对G5V-2继电器开关的控制切换.该系统具有网络通讯集成功能,通过TCP/IP协议,能在局域网内实时监视传感器稳定性测试,并且还能远程控制压力控制器以及调温箱,通过模拟工业现场特定环境中的压力以及温度条件等测试传感器的稳定性.     

The time-triggered architecture

The time-triggered architecture (TTA) provides a computing infrastructure for the design and implementation of dependable distributed embedded systems. A large real-time application is decomposed into nearly autonomous clusters and nodes, and a fault-tolerant global time base of known precision is generated at every node. In the TTA, this global time is used to precisely specify the interfaces among the nodes, to simplify the communication and agreement protocols, to perform prompt error detection, and to guarantee the timeliness of real-time applications. The TTA supports a two-phased design methodology, architecture design, and component design. During the architecture design phase, the interactions among the distributed components and the interfaces of the components are fully specified in the value domain and in the temporal domain. In the succeeding component implementation phase, the components are built, taking these interface specifications as constraints. This two-phased design methodology is a prerequisite for the composability of applications implemented in the TTA and for the reuse of prevalidated components within the TTA. This paper presents the architecture model of the TTA, explains the design rationale, discusses the time-triggered communication protocols TTP/C and TTP/A, and illustrates how transparent fault tolerance can be implemented in the TTA.     

一种可编程嵌入式异步SRAM存储控制器

介绍了一种可编程嵌入式异步SRAM存储控制器的设计与实现方法。从SRAM读写协议、总体设计、各子模块的设计、模拟验证、FPGA实现，及其在数字视频系统中的应用等各个角度，对SRAM控制器的设计方法作了较为全面的介绍。这种设计方法可广泛应用于ASIC芯片、SOC系统等需要嵌入存储控制器的场合。     

Real-time teleconsultation with high-resolution and large-volumemedical images for collaborative healthcare

Real-time consultation between referring physicians or radiologists with an expert is critical for timely and adequate management of problem cases. During consultation, both sides need to: 1) synchronously manipulate high-resolution digital radiographic images or large volume MR/CT images; 2) perform interpretation interactively; and 3) converse with audio. We present a specifically designed teleconsultation system in a digital imaging and communication in medicine picture archiving and communication systems (PACS) clinical environment. The system uses bidirectional remote control technology to meet critical teleconsultation application requirements with high-resolution and large-volume medical images operated in a limited bandwidth network setting. We give the system design and implementation methods, and also describe the teleconsultation procedure and protocol used in this system. Finally, laboratory and clinical evaluation results are discussed     

STM32与上位机Modbus协议的通信方法

由于步进电机控制系统的需要,文中基于Modbus协议,设计了一种PC上位机与STM32下位机之间通信的方法,介绍了STM32的片上外设以及Modbus协议的实现方法,并给出了RS-485通信电路、STM32和上位机的软件设计。通过测试验证了该方法实现了步进电机控制器与PC之间的数据交换,为基于Modbus协议的上、下位机通信系统提供了参考。     

基于以太网的远程数据采集系统设计

针对远程数据采集方面的应用需求,设计了一种基于ARM微处理器的以太网数据采集系统。选取S3C2440作为数据处理器和控制器,DM9000作为网络芯片,在Linux为操作平台下,实现了10位数据采集,并将采集到的数据经过S3C2440的处理,通过以太网传输到服务器上。数据传输采用的网络通信协议是TCP/IP协议,通信过程采用C/S模式。     

Construction of a secure and efficient content key distribution framework for DRM systems

Recent advances in networks and digital technology have provided many user-friendly environments such as telemedicine, e-banking, e-content, and e-commerce. It has revolutionized the multimedia industry and made it accessible anytime and anywhere. However, its limitation also appeared in digital content piracy, which is more prevalent nowadays. Digital rights management (DRM) systems were developed to control the illegal spreading of digital content. Protocols are being developed to enable effective and secure communication in DRM systems. As security and efficiency are essential parameters, the approach should be two birds with one stone; i.e., the protocol should achieve efficiency and security together. Our investigation identified that secure mechanisms either have increased computation/communication overhead or fail to meet specified security criteria when discussing efficient content key delivery mechanisms. So, an efficient protocol design with the right security attributes is required. We have worked on designing a content delivery mechanism keeping in mind the desirable attribute of security and without decreasing overhead. The suggested solution targets “two birds with one stone.” We proved the security of the scheme in the random oracle model. We verify the security against active attacks using the formal simulation tool AVISPA. Detailed analysis is performed for the evaluation of computational and communication overhead. The comparative study is also presented to understand the gains in efficiency and security.     

DMR高层协议在数字对讲机上的实现

DMR通信协议是一个适用于数字集群通信系统的新型通信协议。介绍了在基于DMR通信协议的数字对讲机中DMR高层协议的硬件平台,并在此基础之上详细介绍了DMR高层协议的软件实现。通过实验成功地验证了DMR呼叫控制层(CCL层)协议的完整性与正确性,进而充分说明了DMR协议完全可以使用在数字对讲机以及数字集群通信系统的研发之中。     

基于STM32的PS/2数字键盘通信协议模拟与实现

为了解决数字键盘硬件电路设计的成本和数字键盘模块使用的方便性,使得在工业上具有普遍使用性。通过对PS/2通信协议的研究,利用STM32系列控制器I/O管脚5 V容忍的功能,消除PS/2与STM32电平不一致性,提出一种对PS/2通讯协议模拟方法。该方法采用了软件算法编程,实现了从键盘到STM32数据通讯及功能实现。经过Keil软件仿真及仪表验证,最终得出预期结果。     

Applying IP over wmATM technology to third generation wirelesscommunications

With the rapid development of third-generation wireless mobile communication systems worldwide, the wireless mobile ATM enhanced software radio platform has taken the lead in the implementation process, which helps construct a broadband wireless pipe and “IP over wmATM” open signaling suite to support various common air interfaces for the wireless industry. This article presents the implementational issues using the IP over wmATM solution for 3G broadband wireless mobile communication systems. It includes the design of the wmATM medium access controller, protocol stack, wmATM module definition, and software radio platform, as well as IP unified 3G wireless networks     

数字传声器系统的设计

简述了数字传声器系统的两部分：数据发送端和远程控制端的功能，硬件电路的设计，以及数据发送端和远程控制端之间的通信协议。并对比了数字传声器系统与模拟传声器两者各自的特点。