基于CC—Link网络的PLC控制系统

阐述一种用CC-Link开放式现场总线构成的PLC控制系统.着重介绍该总线的网络特点、功能、通信原理及通信方法,进行了深入的研究,并设计了现场总线应用的控制系统--炉窖网络控制系统.应用结果表明,利用该总线设计的控制系统具有保护功能齐全、通信速率快、实时性好、可靠性高、布线方便等优点,基于CC-Link网络控制系统具有较高的实用价值.     

现场总线

现场总线控制是工业设备自动化控制的一种计算机局域网络。它是依靠具有检测、控制、通信能力的微处理芯片，数字化仪表（设备）在现场实现彻底分散控制，并以这些现场分散的测量，控制设备单个点作为网络节点，将这些点以总线形式连接起来，形成一个现场总线控制系统。它是属于最底层的网络系统，是网络集成式全分布控制系统，它将原来集散型的DCS系统现场控制机的功能，     

现场总线通信控制专用芯片FF-H1研究与开发

本文介绍了FF-H1现场总线通信控制器专用芯片的系统体系结构、工作原理和设计实现.该芯片实现了IEC11582-2/ISA-S50.02物理层和IEC数据链路层底层协议规范,采用0.35微米CMOS工艺设计.下一步将在目前设计的基础上开发基于ARM AMBA总线体系结构的现场总线通信与控制系统芯片的通信控制器IP固核.     

矿山CAN总线数据采集系统的设计

介绍了一种CAN总线数据采集系统的设计。说明了CAN总线的特点，同时阐述了CAN通信节点的组成和通信原理。该系统在工业现场收到了预期的效果。     

现场总线通信控制器专用芯片FF-H1B设计与验证

针对现场总线通信控制器专用芯片进行了更为深入的研究。在分析原有FF-H1设计不足的基础上，FF-H1B采用DMA加片内异步8kB SRAM的体系结构来实现总线通信功能，同时增加了数据链路层处理功能。通过逻辑功能仿真和FPGA原型测试的方法。设计的正确性得到了充分的验证：实际通信效率测试表明，FF-H1B在功能和性能方面较FF-H1有了很大的提高，将能更好的支持现场总线相关应用。     

应用于EPA网络的嵌入式802．11b无线网关

0、引言 针对目前多种现场总线并存的局面，浙大中控原创性地提出了基于以太网的（EPA）（Ethemet for Process Automation）网络通信技术，并主持了国内工业以太网相关标准的制定工作。它针对目前现场总线标准的多样化和非统一性，以及当前现场总线技术的发展和推广存在很大局限的情况，利用国内外现场总线技术和集散控制系统的应用研究成果，结合工业自动化控制的特点，将商用通信领域的以太网技术、IEEE802．11技术、蓝牙技术直接应用于工业现场设备间的通信，以取代目前各种现场总线，而成为新一代统一的现场总线，     

STD前端通信计算机系统

本文介绍一种已付诸运行的以STD总线模板为主构成的前端通信计算机系统。该系统与主机采用前后台配置,实现了多级分布式计算机测控。     

基于变频器的一种协议转换接口设计

随着工厂自动化技术的发展,基于Profibus-DP 现场总线与Modbus协议的通信技术在国内外得到了广泛的应用。然而要实现两者之间数据转换却较为困难,原因是实现两者之间数据转换的产品相对较少。本文针对采用Modbus RTU协议通信的变频器,提供了一种Profibus- DP现场总线与Modbus协议之间转换的通信接口,主要阐述了该接口的软硬件设计方案,并重点介绍了实现通信接口可靠性与实时性的方法。实验结果证明了该设计方案的可行性。     

基于USB总线的CAN总线通信适配器的设计

针对控制系统小尺寸、低功耗的要求，本文首先简述了采用USB总线控制器PDIUSBD12与CAN总线控制器SJA1000设计了基于USB总线的CAN总线通信适配器，并利用WinDriver开发其Windows设备驱动程序。该系统在工业现场可以灵活、高速、高效地完成大量数据交换，并可应用于多种控制系统中。该系统具有极大的应用价值。     

多种现场总线协议在工业生产中的应用与比较

现场总线是指以一定范围内的控制器和执行器间的数据通信为主的网络,也称现场网络.是连接现场自动化设备和智能系统的通信系统.主要解决工业现场的控制器、执行器、智能化终端等现场设备间的数字通信以及这些控制系统和现场控制设备之间的数据传递问题.目前世界上存在着大约四十余种现场总线,本文主要介绍加工制造业常用的PROFIBUS现场总线、MODBUS现场总线和CC-Link现场总线,通过他们的原理、性能参数的对比以及工业现场中维护维修实践,总结以上几种现场总线的实际应用中的优缺点.     

无线现场总线参数配置研究

为了使工业现场总线能够在更复杂的环境中得到应用,研究人员开始试图将无线通信技术融入到工业现场总线中去。以Profibus和IEEE802.11这两种具有代表性的通信标准,在介绍无线现场总线的基本概念和体系结构的基础上,建立时间模型,对令牌持有时间、退避时间元、转发时延等网络参数的配置进行优化。     

Fieldbus-internet connectivity: the SNMP approach

Important reasons for connecting fieldbus systems to IP-based networks are the provision of remote access for monitoring and maintenance purposes, but also the inclusion of automation systems into an enterprise-wide management scope. Existing solutions are chiefly based on Web technology or require specialized, fieldbus-dependent tools. In this paper, the authors propose a different strategy using the standardized and widely used Simple Network Management Protocol. This approach is largely fieldbus-independent and, at the same time, interoperable with existing LAN technology. They discuss the architecture of a protocol conversion gateway and present a modular approach to cope with the variety of available fieldbus protocols. They further propose a structure for a management information base suitable to represent the fieldbus data objects. By means of prototype implementations for different fieldbus systems (Profibus, P-NET, and EIB), they study the influence of the underlying fieldbus communication principles on the gateway implementation and operation     

Real-time fieldbus communications using Profibus networks

This paper provides a comprehensive study on how to use Profibus fieldbus networks to support real-time industrial communications, that is, on how to ensure the transmission of real-time messages within a maximum bound time. Profibus is base on a simplified timed token (TT) protocol, which is a well-proved solution for real-time communication systems. However, Profibus differs with respect to the TT protocol, thus preventing the application of the usual TT protocol real-time analysis. In fact, real-time solutions for networks based on the TT protocol rely on the possibility of allocating specific bandwidth for the real-time traffic. This means that a minimum amount of time is always available, at each token visit, to transmit real-time messages, transversely, with the Profibus protocol, in the worst case, only one real-time message is processed per token visit. The authors propose two approaches to guarantee the real-time behavior of the Profibus protocol: (1) an unconstrained low-priority traffic profile; and (2) a constrained low-priority traffic profile. The proposed analysis shows that the first profile is a suitable approach for more responsive systems (tighter deadlines), while the second allows for increased nonreal-time traffic throughput     

Timer selection for satisfying the maximum allowable delay using performance model of profibus token passing protocol

Recently, the Fieldbus has become an indispensable component for many automated systems. In the Fieldbus system, real-time data containing sensor values and control commands have a tendency to rapidly lose their value as time elapses after its creation. In order to deliver these data in time, the fieldbus network should be designed to have a short delay compared to the maximum allowable delay. Because the communication delay is affected by performance parameters such as the target rotation timer of token passing protocol, it is necessary to select proper parameter settings to satisfy the real-time requirement for communication delay. This paper presents the timer selection method for Profibus token passing networks using a genetic algorithm to meet the delay requirements.     

Go with the right bus [fieldbus selection guidelines]

In the world of fieldbus one could reasonably say that standards are not the be-all and end-all. On the other hand, there are those who would say that their standards are the only realistic choice. However, an alternative selection criterion might be to examine the installed user base and assess which products have been proven and tested in industrial applications. Yet a third option might be to look at the range of commercially available products which the industry is able to offer in support of a specific fieldbus technology. And another valid yard stick could be vendor independence, while the numbers of installed nodes for each fieldbus type represents a further valid parameter of assessment. In summary, selection of a fieldbus type deserves a careful and comprehensive approach. Here, the author presents the case for fieldbus from a Profibus perspective     

PROFIBUS-DP智能从站的研究设计

PROFIBUS现场总线具有通信实时性强、高传输率、低成本、拓扑结构灵活多样、冗余性强、适于各种工控领域等优点而得到广泛应用。针对PROFIBUS现场总线的特点,从开发的角度详细介绍了利用AT89C52单片机与ASIC芯片SPC3设计智能DP从站的方法,并介绍了GSD文件,为PROFIBUS-DP智能从站的简单设计提供了方法。     

Using cut-through forwarding to retain the real-time properties of Profibus over hybrid wired/wireless architectures

The benefits of wireless extensions in industrial networks are well recognized as long as the integration of the wireless and fieldbus domains will be capable of retaining the real-time and dependability quality of the current wired industrial networking solutions. In this paper, the architecture and the operation of a cut-through forwarding device are described, to be used in broadcasting, hybrid wired/wireless Profibus systems. Analytical models of the delay overhead introduced due to frame forwarding are presented. It is shown that the usage of cut-through forwarding devices relaxes the bit-rate requirements in the radio segments, while it drastically improves the inherent advantages and reduces the drawbacks of hybrid transmission media architectures, which are based on a single Medium Access Control domain.     

OSI参考模型与现场总线通信模型的发展与应用

主要介绍了OSI参考模型与现场总线的基本概念及其发展和在工业中的应用，介绍了几种主要的现场总线通信模型与OSI参考模型之间的相互关系。根据现场总线技术在现实中的应用，指出控制系统的开放互连是发展的必然。     

PC作为Profibus-DP单主站的实现

主要介绍Profibus现场总线的基本特性和通信协议，讨论了以PC作为Profibus—DP单主站实现的可行性，并给出了C语言实现的程序。