英文文献 科技类 原文及翻译 （电子 电气 自动化 通信…） 13

外文文献翻译 一、前 言 长期以来，PLC始终处于工业自动化控制领域的主战场，为各种各样的自动化控制 设备提供了非常可靠的控制应用。其主要原因，在于它能够为自动化控制应用提供安全 可靠和比较完善的解决方案，适合于当前工业企业对自动化的需要。另一方面，PLC还必须依靠其他新技术来面对市场份额逐渐缩小所带来的冲击，尤其是工业PC所带来的冲击。PLC需要解决的问题依然是新技术的采用、系统开放性和价格。 PLC技术展的最终趋势仍然是人们所争论的焦点之一。大多数人认为，PLC将会继续失去市场份额；更有甚者认为，在工业PC面前，PLC将会一步一步走向死亡；但也有 一部分人相信，一些特殊工业应用领域仍将为PLC提供一定的市场份额。 在全球工业计算机控制领域，围绕开放与再开放过程控制系统、开放式过程控制软 件、开放性数据通信，已经发生巨大变革，几乎到处都有PLC，但这种趋势也许不会继续发展下去。随着软PLC(SoftPLC)控制组态软件技术的诞生与进一步完善和发展， 安装有SoftPLC组态软件和基于工业PC控制系统的市场份额正在逐步得到增长，这些 事实使传统PLC供应商在思想上已经发生了戏剧性的变化，他们必须面对现实，在传统 PLC的技术发展与提高方面作出更加开放的高姿态。对于控制软件来讲，这是PLC控制器的核心，PLC供应商正在向工业用户提供开放式的编程组态工具软件，而且对于工业 用户表现得非常积极。此外，开放式通信网络技术也得到了突破，其结果是将PLC融入更加开放的工业控制行业。 二、开放和基于工业PC控制 PLC制造商已经开始注视基于工业PC控制技术所带来的强大冲击。有专家甚至认 为，新商务活动所带来的新技术和开放技术将会埋葬传统PLC。PLC制造商认为，虽然在工业现场安装有大量的PLC控制设备，但他们仍然需要联合工控软件公司，以便 开发他们自己的基于工业PC的过程控制软件。 诚然，几年前在工业现场明显存在着新旧PLC混合使用的情况，工业用户不得不同 时学习相关的新旧知识，甚至彼此借鉴学习。大多数PLC制造商为工业用户仅仅提供了 软逻辑和一种操作平台。 在高端应用方面，很难进一步区分PLC控制系统和工业PC控制系统之间的差异， 因为这两者均采用了同样类型的微处理器和内存芯片。形象地打个比喻，如果你忘掉工 业PC和PLC这些词语字面上的含义，那么在箱子里所能够观察到的恰恰是一些基本计 算机硬件技术，我们更多观察到的却是那些基本技术的复杂化和混合体，这些技术被有 效地组合到控制系统中去。 另外，采用开放控制的原因一方面是系统功能集成的需要，另一方面也是由于一些 工业用 户对功能过分苛求所致。如果能够给予高度的重视，就能够获得更多的基本技 术知识。PLC制造商专注于系统功能化，而工业用户则专注于系统应用。人们可以看到， 将来的发展趋势是将更多的功能进一步集成到一个控制箱内。因而像顺序控制和过程控 制这样的事件将会采用功能化方式进行处理，其他像运动控制等也能够共享到相同的控 制结构体系中。 可以相信，PLC技术将继续向开放式控制系统方向转移，尤其是基于工业PC的控制系统。后者除了在灵活性方面比传统PLC具有截然不同的优势外，还具有其他优点，如 能够缩短系统投放到市场的周期，降低系统投资费用，提高从工厂底层到企业办公自动 化的数据信息流动效率等。 关于工业PC控制系统的实时响应问题已经得到很好的解决，也许其主要的东西仍 然隐藏在技术背后，但缺乏相应的跟踪记录。对于PLC来讲，坚固性是其主要特点之一，这已经有相当多的跟踪记录来验证。工业用户仍然非常小心地对待PLC，他们正在对PLC 作不同的技术测试工作。在利用一种新技术时，工业用户需要考虑的问题是要冒多大的 风险，同时需要考虑对其商务活动能够带来多少机会和收益。 但工业用户不完全相信开放式控制系统所带来的好处。随着技术的进一步发展，他 们开始逐渐淡化这些思想观念。工业用户正在平衡采用新技术所存在的风险和给他们的 商务活动所带来的收益，以便为今后的决策提供有效的保障。 工业PC技术提供了许多功能，能够增强PLC的功能特性，包括内藏视频和高速浮 点数字协处理器。尽管Microsoft公司没有进一步提升该项功能特性的计划，但新的 Windows CE 3.0完全能够更好地满足过程控制的需要。 不久前，Siemens公司公布了一套新的基于开放式控制系统的软件产品，即3.0版 本的SIMATIC WinAC(Windows自动化中心)。WinAC是基于Windows NT，与SIMATIC S7 PLC兼容的适合于工业PC的控制系统解决方案。WinAC 3.0提供了具有较高集成度的Profibus现场总线局域网的连接性能，以及远程程序。此外，它还为现场控制设备 1 本地化集成提供了一种新的DeviceNet I/O设备驱动程序，用于连接所安装的DeviceNet I/O设备。 Steeplechase软件公司也已推出了一套支持硬实时过程控制的嵌入式Windows NT操作系统接口部件。该部件进一步结合了Steeplechase公司采用SBS技术并运行于Windows NT环境的工业Compact PCI的硬实时控制软件。现在，Steeplechase公司的可视化逻辑控制器已经升级到5.0版。该控制器适合于Windows NT 4.0和Windows 2000两种操作系统，它的实时引擎能够直接与普通的Ethernet和TCP/IP集成在一起。5.0版本的控制器利用了一种增强型OPC服务器驱动程序，因而比以前的版本具有更快的运 行速度。其他一些特点还包括新OI网络特性，以及能够让工业用户自己设计出丰富多 彩的动态图形画面等。 Transysoft公司最近推出了新版本的ISaGRAF系列工业控制组态软件包，即 ISaGRAF PRO，它是基于IEC 61131-3国际，并独立于任何硬件平台的软逻辑自动 化控制软件包。在一个网络化过程控制系统环境中，该软件包能够应用于多种组态和分 布式控制系统的开发，它包含了一套开发工具、应用程序工作平台，以及相应的“虚拟 机器”运行时目标。该运行时目标能够运行于各种各样的硬件平台。 CTC自动化工程公司已经发布了一套新的控制软件包MachineLogic PCLC（工业PC逻辑控制器），该软件可以让工业PC扮演PLC的角色，且仍然保持着工业PC的功能特性。该软件能够完成一台PLC所确定的控制任务，并且与程序执行时间一样快，均在1 ms以内；还能够同时处理多任务工作，但不能同时超过16个控制任务。一种具有优先级 和多任务处理内核的机制保持着对每一件控制任务的跟踪，确保控制任务能够取得最高 的优先权。该软件能够运行全部5种IEC 61131-3标准程序设计语言和PID控制程序，支持两种类型的I/O控制设备。一种是像Profibus和DeviceNet等这样的现场总线I/O设备；另一种是像ISA和PC/104这样的工业PC I/O模板。另外，该软件还提供了对控 制系统的在线编辑组态功能。程序可以在Windows 95/98和Windows NT下开发并运行，但也能够在RTXDOS下执行。 SoftPLC公司也提供了一种工控软件产品Tealware，有人非常形象地把这种软件产 品称作穿着工业PC衣服的PLC。那些安装在支架上的控制系统已经有了小型PLC的形状系数，但SoftPLC公司的控制软件已经被嵌入到CPU中。Tealware软件能够满足各种类型工业用户的需要，从小型、单机系统到大型、分散多控制工作站应用。其特点包括全 2 系列I/O模件、内藏Ethernet和工业串行通信接口。 最近，Tealware软件已经升级到2.3版本。其中，控制软件提供了事实上无限的梯 形图逻辑控制步序，同时允许有超过百万字的数据表；许多OI/SCADA应用接口；内藏Java引擎和FTP服务器用于远程维护与管理；支持用户自己编写的C、C++、Java程序和设备驱动程序；适合于嵌入式Web服务器用；程序设计的在线运行模式；坚固的I/O模件支持能力和许多其他标准PLC功能；可以运行所输入的，或者是经过转换的A-B公司的PLC-5、PLC-2/PLC、PLC-3和SLC-500程序。 三、Ethernet的扩展与进一步容纳Web技术 当前，在所有过程控制领域，最大的发展趋势之一就是Ethernet技术的扩展。PLC也例外，现在，越来越多的PLC供应商开始提供Ethernet接口部件。在最近的几年间， 我们已经看到，发展比现有普通小快灵PLC更加强大的PLC是种趋势。Ethernet将会成为PLC的通信标准吗？也许最终结果是这样的，但现在还为时尚早。对于在PLC上提供Ethernet接口将能够解决所有通信问题，人们普遍存在着误解。Ethernet仅仅定义了OSI参考模型底部的几层协议标准，如果上层协议相互之间不能兼容，那么仍然不可能 进行相互之间的通信处理。打个比方，这如同一个不懂英语的中国人与一个不懂汉语的 美国人之间是不能够通过电话进行对话一样。因此，协议就是设备之间相互通信的语言。 另一方面，前进的步伐已经迈出，我们只有迎着困难而上，为了将Ethernet技术应用到工厂底层的现场过程控制设备中去，ODVA协会为此建立了一套全球性标准技术规 范，即Ethernet/IP标准，以便能够解决在实际工作中所遇到的困难。 向Ethernet靠近的一个目的在于通过Internet能够连接到所希望的任何地方。实 际上，在一些意想不到的地方，Web服务器正在显露出其应有的威力。几年前，有一些 PLC系统已经内藏了Web服务器，这无疑又为PLC系统增加了更多的特点。其他类型的 控制设备也正在准备进一步集成Web服务器。例如，Square D公司已经有一个具备Ethernet连接接口的发动机控制中心，并正在准备开发一种内藏Web服务器连接接口的变速装置。 内藏Web服务器所体一风的益处包括开放网络、商业工具的影响、客户机/服务器关系。在过去，工业用户可能会有代表性地询问一些有关PLC方面的信息，但在现在， 由于新技术的不断诞生和发展，工业用户很容易就可以得到有关这方面的信息。另一方 面，随着芯片和处理器大规模的生产，PLC生产制造商能够生产并提供开放网络的产品， 3 让工业用户花较少的费用就能够购买到功能非常完善的PLC产品。 在为将PLC连接到Ethernet和Web上提供技术支持方面，Schneider公司已经成了先驱者之一。最近，该公司推出了一种运行于Premium PLC平台的新型快速Ethernet(100 Mb/s)模件。该模件为PLC能够连接到TCP/IP的Ethernet提供了全双工自适应 10/100Mb/s的连接速度，现场过程控制器之间可以共享实时数据信息，自动扫描 Momentum I/O模件和其他任何基于Modbus通信协议的现场控制设备，采用一个嵌入式 Web服务器提供HTML通信服务，同时提供了SNMP用于标准网络通信管理。在一次展览 会上，Schneider公司还向工业用户展示了他们有关透明工厂的观念。另外，Schneider公司最近还推出了基于Modicon公司的Momentum MIE系列处理器的适配器，该适配器 提供了标准IEC程序控制性能，进一步为e-制造提供了完美的解决方案。该适配器还提 供了将智能化I/O系统和其他现场过程控制设备连接到Internet和Ethernet的能力，现场过程控制设备包括所有功能化实时过程控制器。 几年前，Rockwell自动化公司也在其PLC产品中提供了Ethernet接口，而且正在坚定不移地稳步提高Ethernet的功能特性。该公司最近已经公布了一种柔性I/O模件解决方案，这种柔性I/O模件利用非专利版本的Ethernet技术能够提供实时过程控制 性能。A-B公司提供的1756型ControlLogix I/O也是基于标准Ethernet TCP/IP和UDP数据传输协议的组件，其应用层使用了一种开放式、面向对象、基于生产者/ 消费者的技术。这种技术在ControlNet、DeviceNet和FF现场总线H1网络系统中也能够找到。 同样，其他许多公司也已经推出了Ethernet通信接口模件。例如，来自于IDEC公司的OpenNet PLC控制器所提供的通信接口，实现了与DeviceNet、LonWorks和Interbus等现场总线设备的兼容。该控制器利用一个Interbus远程I/O主卡件能够处理不超过 480点本地I/O和512点远程数字量I/O。 Sierra公司所提供的8051型工业通信桥路能够让彼此之间互不兼容的PLC、DCS、RTU和SCADA系统很好地集成在一起。这种工业通信桥路通过RS-232、422、485，或者Ethernet通信链路实现了高速网络应用。该桥路控制器同时提供8个RS-232串行通信接口，2个RS-485/422隔离串行通信接口，2个10Base-T Ethernet接口，以及一个用于冗余热备份桥路的连接器。 来自于ProSoft公司的多制造商接口套装组件为A-B公司的PLC、SLC、ControlLogix和FLEX I/O（包括1771、1746、1765和1794）平台提供了串行通信能力。每一个模件 4 包含了一个80386处理器，并同时嵌入有DOS操作系统，因而，可以被看作是具有I/O能力的工业PC，另外，该控制器同样具有“A>”磁盘操作提示符，以及Autoexec.bat和Config.sys文件。应用程序可以是从简单的ASCII通信到复杂的32位控制算法。 另一家通常从事运动控制方面研究的公司Giddings & Lewis也为其PiC（可编程工业控制）和MMC（机械与运动控制）系列应用于运动控制方面的产品增加了Ethernet TCP/IP接口。这些单元部件提供了可以连接到工厂内部Intranet和Internet的能力，允许现场过程控制器之间共享数据信息。现场过程控制器与工业PC之间通常采用OPC服务器设备驱动程序来连接实时数据信息，利用Ethernet网络系统和Web技术可以进行远程文件传输、程序设计和系统维护。 现在，越来越多的企业正在计划将其所有自动化控制设备逐步连接到企业范围内的 信息系统中去。对于工业用户来讲，也许他们已经注意到有关Ethernet for Control 系列控制解决方案，该技术更加依赖于Ethernet和Internet。几乎所有PLC供应商在其部分系列化产品中均提供了Ethernet连接特性，而且有些公司已经确定将Web服务器彻底嵌入到他们的设备内部，以便充分展现PLC的性能特点。利用PLC的Web连接特性，工业用户不但可以从任何地方监控控制系统的运行状况，而且还可以像利用系统手 册一样获取所需要的任何数据信息。 当然，如果工业用户正在着手将其控制系统连接到Internet，则必须为此设置安全 的信息发布地址。另外，为了防止黑客进入到控制系统中去，还必须安装一套安全性能 较好的防火墙软件。 SoftPLC公司在网络安全性方面投入了极大的热情和兴趣，他们将一个具有实时和 确定性的Java虚拟机器嵌入到过程控制器中去。Java使其不仅能够运行基于Web的Active X控件对象，同样也能够运行Servlets。Servlets是个运行于Web服务器任务高度集成在一起，能够提供动态Web页面。Servlets程序代码清晰可见、面向对象 设计、模件化，开发起来非常简单明了，Servlets也提供了数据信息安全性能，允许进 一步限制实时数据信息，如仅仅是所选定的工业用户，或者是所选定的注册数据信息。 如果过程控制器被有效地连接到Internet，那么安全性对其是非常的重要。 黑客的入侵还不是唯一的烦恼，如果网络系统瘫痪，我们首先需要干什么呢？黑客 入侵的解决方案是采用冗余。在过程控制器中采用冗余IP地址、冗余网络系统、冗余 通信电缆，以及热备份等方式，当突发事件发生时能够很好地为过程控制系统提供服务。 5 许多PLC供应商在其产品的开发过程中仍然继续不断地改进和提高通信性能，其开 发方向主要面向于Ethernet技术和基于Web技术。 I. Introduction For a long time, PLC will always be in the field of industrial automation and control the main battlefield for a variety of automated control equipment to provide a very reliable control applications. The main reason is that it can provide for the automation control applications safe, reliable and relatively perfect solution for the current industrial enterprises in automation needs. 6 On the other hand, PLC must also rely on other new technologies to deal with shrinking market share gradually brought about by the impact, in particular the PC industry brought about by the impact. PLC need to address the problem still is the introduction of new technology, the system of open and prices. PLC technology exhibition is the ultimate trend that people are still the focus of controversy. Most people think, PLC will continue to lose market share; What is more, in the face of industrial PC, PLC will be step by step towards death, but there are some people believe that some special industrial applications for the PLC will continue to provide a certain market share . In the global industrial computer-controlled areas, and re-open around the open process control system, open process control software, data communication protocol and opening up, enormous changes have taken place almost everywhere PLC, but this trend may not continue to develop. With the soft PLC (SoftPLC) configuration control software technology and the birth of further improvement and development, installation and configuration software is SoftPLC PC-based industrial control system's market share is gradually growing, the fact that traditional suppliers in terms of ideology PLC Have taken place in the dramatic change, they must face the reality, the traditional PLC technology development and raising more open to make a high-profile. The control software, this is the core of PLC controller, PLC providers are available to industrial users of open programming configuration tools, but also for industrial users was very positive. In addition, open communication network technology has also been a breakthrough, the result is the PLC into a more open industrial control industries. Second, open and PC-based industrial control PLC manufacturers have started watching PC-based industrial control technology brought about by the powerful impact. Some experts even believe that the new business brought about by new technology and open technical specifications will be buried traditional PLC. PLC manufacturers that, although in the industrial field installation of a large number of PLC control equipment, 7 but they still need the Joint Control software companies to develop their own PC-based industrial process control software. It is true that a few years ago in the industrial scene obviously there is a mix of the old and the new PLC, industrial users have to learn related to the old and new knowledge, learning and even learn from each other. The majority of PLC manufacturers for industrial users provide only a soft logic and a platform. In the high-end applications, it is difficult to distinguish between PLC control systems and industrial PC control system the difference between, because it both followed the same types of microprocessors and memory chips. Play the image of an analogy, if you forget the industrial PC and PLC literal meaning of those words, then the box can observe it is precisely some of the basic computer hardware technology, we observed that the more it is the complexity of those basic skills And the mixture of these technologies to be effective in combination to control system. In addition, the adoption of the reasons for the control system functions on the one hand is the need for integration, on the other hand also because some industrial users to function due to excessively demanding. If we can give a high degree of attention, we can get more of the basic technical knowledge. PLC manufacturers to focus on system functions, while industrial users will focus on system applications. People can see that the future trend of development is to further integrate more functions to a control box. As a result sequence control and process control such incidents will be used functional approach to deal with, like the other sports can also share control of the control structure to the same system. It is believed that, PLC technology will continue to open the direction of transfer control system, in particular, the PC-based industrial control systems. The latter addition to the flexibility than traditional PLC has distinct advantages, but also has other advantages, such as the system can be shortened 8 to hit the market cycle, lower system cost of investment, improve the bottom from the factory to the corporate office automation efficiency of the data flow of information And so on. On industrial PC control system for real-time response has been very good solution, perhaps the main thing is still hidden behind in technology, but the lack of corresponding track record. The PLC speaking, the strength of one of its main features, this is already a considerable number of track records to verify. Industrial users will still treat very carefully PLC, they are different from the PLC for the technical tests. In the use of a new technology, industrial users need to consider the question of how much is take the risk, and the need to consider their business activities can bring the number of opportunities and benefits. However, industrial users are not completely believe that the open-control system brought about by the benefits. With the further development of technology, they began to gradually reduce these ideas and concepts. Industrial users are balanced by the introduction of new technology and the risks to their business activities brought about by the proceeds from the future decision-making in order to provide effective protection. Industrial PC technology offers many features to enhance the PLC features, including containing digital video and high-speed floating-point coprocessor. Although Microsoft did not further enhance the features of the plan, but the new Windows CE 3.0 entirely to better meet the needs of process control. Not long ago, Siemens announced a new set of control system based on open software products, that is, 3.0 version of the SIMATIC WinAC (Windows Automation Center). WinAC is based on Windows NT, and SIMATIC S7 PLC-compatible PC suitable for industrial control system solutions. WinAC 3.0 provides a higher degree of integrated Profibus Fieldbus LAN connectivity, and remote programming. In addition, it was the scene of control equipment localization integration provides a new DeviceNet I / O device driver, used to connect the installed 9 DeviceNet I / O devices. Steeplechase software company has also introduced a set of hardware support for real-time process control of embedded Windows NT operating system interface components. Parts of the further integration of the Steeplechase company SBS technology and run the Windows NT environment in the industrial Compact PCI hardware real-time control software. Now, Steeplechase's visual logic controller has been upgraded to version 5.0. The controller for Windows NT 4.0 and Windows 2000 operating systems of two of its real-time engine directly with ordinary Ethernet and TCP / IP integrated. 5.0 version of the controller using a enhanced OPC server drivers, so than the previous version with a faster speed. Other features include a new network of OI, and to allow industrial users to design their own colorful screen, such as dynamic graphics. Transysoft company recently launched a new version of the ISaGRAF series of industrial control configuration package, that is ISaGRAF PRO, it is based on IEC 61131-3 international standards and independent of any hardware platform logic of automatic control of the soft package. In a network environment in the process control system, the package can be applied to a variety of configurations and the development of distributed control system, which includes a set of development tools, application platform and the corresponding "virtual machine" run-time目标. The run-time goal to run on a variety of hardware platforms. CTC automation engineering company has released a new set of control package MachineLogic PCLC (industrial PC logic controller), the PC software industry can play a role in the PLC, and remain industrial PC features. The software able to complete a set by the PLC control tasks, and procedures for the implementation of time and as fast, both in less than 1 ms; can handle more tasks, but not more than 16 control tasks. Is a priority and multi-tasking core mechanism for maintaining control of every one of the tasks of tracking and control tasks can be made to ensure that the highest priority. The software can run all five IEC 61131-3 standard programming languages and PID control procedures, to support 10 two types of I / O control equipment. One is like Profibus and DeviceNet, such as the Fieldbus I / O devices, the other is like PC/104 ISA and the industrial PC I / O template. In addition, the software also provides a control system configuration editor of the online features. Procedures in Windows 95/98 and Windows NT, developed and run, but also in RTXDOS under implementation. SoftPLC company also provides a software industrial products Tealware, it was the very image of the software products such as wearing clothes of the PC industry PLC. Stent installed in the control system has a small form factor of the PLC, but SoftPLC's control software has been embedded in the CPU. Tealware software to meet the needs of various types of industrial users, from small, stand-alone systems to large, decentralized and more control workstation applications. The distinctive features include the full range of I / O module, containing industrial Ethernet and serial communication interface. Recently, Tealware software has been upgraded to version 2.3. Among them, in fact control software provides a limitless ladder logic control sequence, while allowing more than 1 million characters of data table; many OI / SCADA application interface; containing Java engine and FTP server for remote maintenance and management; support Prepared by the user's own C, C + +, Java procedures and device drivers; suitable for embedded Web server; programming online mode; rugged I / O modules to support capacity and many other standard features PLC; can run by the Entered, or the conversion of the AB's PLC-5, PLC-2/PLC, PLC-3 and SLC-500 procedures. Third, Ethernet and further to accommodate the expansion of Web technology At present, in all areas of process control, one of the biggest trends is the expansion of Ethernet technology. PLC also an exception, now, more and more providers begin to provide PLC Ethernet interface components. In the past few years, we have seen, the development of small faster than the existing general Ling PLC PLC is a more powerful kind of trend. PLC Ethernet will become the communication standards? ? Perhaps this is the end result, but now it is still 11 too early. In the PLC to provide Ethernet interface will be able to solve all the communication problems, widespread misunderstanding of the people. Ethernet only definition of the OSI reference model at the bottom of the layers of protocol standards, if the upper agreement can not be compatible with each other, then still impossible to handle communications between the two. Example, that as a Chinese who do not understand English with a Chinese-Americans do not know can not be between the phone like a dialogue. Therefore, the agreement between the communications equipment that is the language. On the other hand, the pace of progress has been made, we only facing difficulties, in order to Ethernet technology will be applied to the bottom of the plant site to process control equipment, ODVA Association for the establishment of a global standard specifications, Ethernet / IP standards, in order to be able to solve the practical work of the difficulties encountered. Ethernet and around to a view to the Internet can connect to the desired anywhere. In fact, in some unexpected places, Web server is demonstrating its rightful power. A few years ago, a number of PLC systems have built a Web server, this is undoubtedly also for the PLC has added more features. Other types of control equipment are also ready to further integrate Web server. For example, Square D company already has a connection with Ethernet interface of the engine control center and is preparing to develop a Web server containing the speed interface devices. Built by the Web server of a wind of the benefits include the open network, the impact of commercial tools, client / server relationship. In the past, industrial users may be representative of the PLC asked some of the information, but now, because of the continuous birth of new technology and development, industrial users can easily get the information in this regard. On the other hand, as the processor chip and large-scale production, PLC product manufacturers to provide an open network and the production of products for industrial users spent less the cost will be able to function very well to the purchase of the PLC products. 12 For the PLC will connect to Ethernet and on the Web to provide technical support, Schneider has become one of the pioneers. Recently, the company introduced a Premium PLC platform running on the new fast Ethernet (100 Mb / s) module. The module can be connected to the PLC for the TCP / IP Ethernet provides the adaptive full-duplex 10/100 Mb / s connection speed, on-site process controller can be shared between the real-time data, automatic scanning Momentum I / O module And any other Modbus communication protocol based on the control equipment at the scene, using an embedded Web server to provide HTML communications services, while providing a standard SNMP for network communications management. In a show, Schneider also industrial users to display their factories on the concept of transparency. In addition, Schneider has also recently launched a company based on the company's Momentum MIE Modicon family of processors adapter, the adapter provides a standard IEC controlled performance, and further to provide e-create the perfect solution. The adapter will also provide intelligent I / O system and other process control equipment at the scene connected to the Internet and Ethernet capacity, on-site process control equipment, including all the features of real-time process controller. A few years ago, Rockwell Automation also provide its PLC products in the Ethernet interface, and is firmly steady increase in Ethernet features. The company recently announced a flexible I / O module solutions, such flexible I / O module using the generic version of Ethernet technology can provide real-time process control performance. AB 1756 provides the type ControlLogix I / O is also based on standard Ethernet TCP / IP and UDP data transmission components of the agreement, the application layer using an open, object-oriented, based on the producer / consumer technology. This technology in ControlNet, DeviceNet and FF H1 fieldbus network system also can be found. Similarly, many other companies have also launched a communications Ethernet interface module. For example, from IDEC's OpenNet PLC controller provided by 13 the communications interface, with the realization of DeviceNet, LonWorks and Interbus, and other Fieldbus-compatible equipment. The controller uses a Interbus Remote I / O card were not able to handle more than 480 points of local I / O and 512 points remote digital I / O. Sierra provided by the company's 8051 industrial communication bridge between them to allow non-compliant PLC, DCS, RTU and SCADA systems well integrated. Road communication through this industrial RS-232, 422,485, or Ethernet communication links to achieve high-speed network applications. The bridge controller at the same time provide eight RS-232 serial communication ports, two RS-485/422 isolated serial communication ports, two 10 Base-T Ethernet interface and a redundant hot backup for the Road The connector. From ProSoft's multi-component manufacturers interface package for the AB's PLC, SLC, ControlLogix and FLEX I / O (including 1771,1746,1765 and 1794) provided a platform for serial communication capabilities. Each module contains a 80386 processor, and at the same time embedded in a DOS operating system, thus, can be seen as with I / O capability of industrial PC, In addition, the same controller with "A>" prompt disk operation And Autoexec.bat and Config.sys file. Applications can be from simple ASCII communications to complex control algorithms 32. Another campaign is usually in control of the company on Giddings & Lewis also for PiC (programmable industrial control) and MMC (machinery, and movement control) series for the motion control products increased by Ethernet TCP / IP interface. Parts of these units can be provided to connect to the Internet and Intranet within the plant's ability to process the scene to allow sharing of data between the controller. The scene and industrial process controllers are usually used between the PC OPC server device drivers to connect to real-time data, using Ethernet network systems and Web technology for remote file transfer, process design and system maintenance. Now, more and more enterprises are planning to gradually all automation 14 control equipment connected to the enterprise-wide information system to. The terms of industrial users, perhaps they have already taken note of the Ethernet for Control Series control solutions, the technology more dependent on Ethernet and Internet. Almost all PLC providers in some of its products in both series provides Ethernet connectivity, and some companies have been identified will be embedded in Web server to complete their internal equipment, the PLC in order to fully demonstrate the performance characteristics. PLC use of Web connectivity features, not only from industrial users anywhere in the operation control system monitoring the situation, but also like the use of manual systems as required to obtain any data information. Of course, if industrial users is in the process of its control system connected to the Internet, must be set up for this release address information security. In addition, in order to prevent hackers access to the control system, must also install a better firewall security software. SoftPLC in the network security company has invested a great deal of enthusiasm and interest, they will have a real-time and uncertainty of the Java virtual machine embedded controller to the process. Java so that it can not only run Web-based Active X control targets, the same can also run Servlets. Servlets is a Web server running on with the task of highly integrated, dynamic Web pages can provide content. Servlets code clearly visible, object-oriented design, modules, developed with a very clear and simple, Servlets also provides data and information security, to allow further restrictions on real-time data, such as only a selected industrial users, or by Selected registration data. If the process controller is effectively connected to the Internet, so their security is very important. Hackers invaded is not the only problem, if the network system paralyzed, we first need to do it ? Hacking solution is to use redundant. In the process controller redundancy in the use of IP addresses, redundant network systems, redundant communications cables, as well as hot backup mode, when unexpected 15 events can be a good time for the process control system to provide services. Many PLC suppliers in its product development process is still continuing to improve performance and enhance communication, the development-oriented in the direction of the main Ethernet technology and Web-based technology. 16