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1、中文:dcsdcs是分布式控制系统的英文缩写(distributed control system),在国内自控行业又称之为集散控制系统。即所谓的分布式控制系统,或在有些资料中称之为集散系统,是相对于集中式控制系统而言的一种新型计算机控制系统,它是在集中式控制系统的基础上发展、演变而来的。它是一个由过程控制级和过程监控级组成的以通信网络为纽带的多级计算机系统,综合了计算机,通信、显示和控制等4c技术,其基本思想是分散控制、集中操作、分级管理、配置灵活以及组态方便。在系统功能方面,dcs和集中式控制系统的区别不大,但在系统功能的实现方法上却完全不同。首先,dcs的骨架系统网络,它是dcs的基础和
2、核心。由于网络对于dcs整个系统的实时性、可靠性和扩充性,起着决定性的作用,因此各厂家都在这方面进行了精心的设计。对于dcs的系统网络来说,它必须满足实时性的要求,即在确定的时间限度内完成信息的传送。这里所说的“确定”的时间限度,是指在无论何种情况下,信息传送都能在这个时间限度内完成,而这个时间限度则是根据被控制过程的实时性要求确定的。因此,衡量系统网络性能的指标并不是网络的速率,即通常所说的每秒比特数(bps),而是系统网络的实时性,即能在多长的时间内确保所需信息的传输完成。系统网络还必须非常可靠,无论在任何情况下,网络通信都不能中断,因此多数厂家的dcs均采用双总线、环形或双重星形的网络拓
3、扑结构。为了满足系统扩充性的要求,系统网络上可接入的最大节点数量应比实际使用的节点数量大若干倍。这样,一方面可以随时增加新的节点,另一方面也可以使系统网络运行于较轻的通信负荷状态,以确保系统的实时性和可靠性。在系统实际运行过程中,各个节点的上网和下网是随时可能发生的,特别是操作员站,这样,网络重构会经常进行,而这种操作绝对不能影响系统的正常运行,因此,系统网络应该具有很强在线网络重构功能。其次,这是一种完全对现场i/o处理并实现直接数字控制(ddc)功能的网络节点。一般一套dcs中要设置现场i/o控制站,用以分担整个系统的i/o和控制功能。这样既可以避免由于一个站点失效造成整个系统的失效,提高
4、系统可靠性,也可以使各站点分担数据采集和控制功能,有利于提高整个系统的性能。dcs的操作员站是处理一切与运行操作有关的人机界面(hmi-human machine interface或operator interface)功能的网络节点。工程师站是对dcs进行离线的配置、组态工作和在线的系统监督、控制、维护的网络节点,其主要功能是提供对dcs进行组态,配置工作的工具软件(即组态软件),并在dcs在线运行时实时地监视dcs网络上各个节点的运行情况,使系统工程师可以通过工程师站及时调整系统配置及一些系统参数的设定,使dcs随时处在最佳的工作状态之下。与集中式控制系统不同,所有的dcs都要求有系统组
5、态功能,可以说,没有系统组态功能的系统就不能称其为dcs。dcs自1975年问世以来,已经经历了二十多年的发展历程。在这二十多年中,dcs虽然在系统的体系结构上没有发生重大改变,但是经过不断的发展和完善,其功能和性能都得到了巨大的提高。总的来说,dcs正在向着更加开放,更加标准化,更加产品化的方向发展。作为生产过程自动化领域的计算机控制系统,传统的dcs仅仅是一个狭义的概念。如果以为dcs只是生产过程的自动化系统,那就会引出错误的结论,因为现在的计算机控制系统的含义已被大大扩展了,它不仅包括过去dcs中所包含的各种内容,还向下深入到了现场的每台测量设备、执行机构,向上发展到了生产管理,企业经营
6、的方方面面。传统意义上的dcs现在仅仅是指生产过程控制这一部分的自动化,而工业自动化系统的概念,则应定位到企业全面解决方案,即total solution 的层次。只有从这个角度上提出问题并解决问题,才能使计算机自动化真正起到其应有的作用。dcs具有以下特点:(1) 高可靠性。由于dcs将系统控制功能分散在各台计算机上实现,系统结构采用容错设计,因此某一台计算机出现的故障不会导致系统其他功能的丧失。此外,由于系统中各台计算机所承担的任务比较单一,可以针对需要实现的功能采用具有特定结构和软件的专用计算机,从而使系统中每台计算机的可靠性也得到提高。(2) 开放性。dcs采用开放式,标准化、模块化和
7、系列化设计,系统中各台计算机采用局域网方式通信,实现信息传输,当需要改变或扩充系统功能时,可将新增计算机方便地连入系统通信网络或从网络中卸下,几乎不影响系统其他计算机的工作。 error! no bookmark name given.dcs的发展历史dcs是分布式控制系统的英文缩写(distributed control system),在国内自控行业又称之为集散控制系统。它是一个由过程控制级和过程监控级组成的以通信网络为纽带的多级计算机系统,综合了计算机(computer)、通讯(communication)、显示(crt)和控制(control)等4c技术,其基本思想是分散控制、集中操作
8、、分级管理、配置灵活、组态方便。)它的发展大体分为三个阶段。第一阶段:1975-1980年,在这个时期集散控制系统的技术特点表现为:1)采用微处理器为基础的控制单元,实现分散控制,有各种各样的算法,通过组态独立完成回路控制,具有自诊断功能2)采用带crt显示器的操作站与过程单元分离,实现集中监视,集中操作3)采用较先进的冗余通信系统第二阶段:19801985.,在这个时期集散控制系统的技术特点表现为:1)微处理器的位数提高,crt显示器的分辨率提高2)强化的模块化系统3)强化了系统信息管理,加强通信功能第三阶段,1985年以后,集散系统进入第三代,其技术特点表现为:1)采用开放系统管理2)操作
9、站采用32位微处理器3)采用实时多用户多任务的操作系统进入九十年代以后,计算机技术突飞猛进,更多新的技术被应用到了dcs之中。plc是一种针对顺序逻辑控制发展起来的电子设备,它主要用于代替不灵活而且笨重的继电器逻辑。现场总线技术在进入九十年代中期以后发展十分迅猛,以至于有些人已做出预测:基于现场总线的fcs将取代dcs成为控制系统的主角。dcs是 data communication subsystem (数据通信子系统)的简称。以轨道交通行业为例,dcs是一个纯透明的非安全性系统,他是控制中心和列车之间发送报文的载体。dcs第二层涵义:dorsal column stimulator医脊柱刺
10、激器在特殊控制领域,如核电站控制系统,dcs的含义为数字化控制系统(digital control system)。国内dcs主要厂家有:上海新华,鲁能控制,国电智深,浙大中控,和利时,上海华文,上海乐华,浙江中自等。国外的有 西屋(艾默生)、foxboro、abb、西门子、霍尼韦尔、横河、山武霍尼韦尔公司、fisher-rosemount公司等 error! no bookmark name given.dcs特点和发展概述dcs是分散控制系统(distributed control system)的简称,国内一般习惯称为集散控制系统。它是一个由过程控制级和过程监控级组成的以通信网络为纽带的
11、多级计算机系统,综合了计算机(computer)、通讯(communication)、显示(crt)和控制(control)等4c技术,其基本思想是分散控制、集中操作、分级管理、配置灵活、组态方便。dcs具有以下特点:(1)高可靠性 由于dcs将系统控制功能分散在各台计算机上实现,系统结构采用容错设计,因此某一台计算机出现的故障不会导致系统其它功能的丧失。此外,由于系统中各台计算机所承担的任务比较单一,可以针对需要实现的功能采用具有特定结构和软件的专用计算机,从而使系统中每台计算机的可靠性也得到提高。(2)开放性 dcs采用开放式、标准化、模块化和系列化设计,系统中各台计算机采用局域网方式通信
12、,实现信息传输,当需要改变或扩充系统功能时,可将新增计算机方便地连入系统通信网络或从网络中卸下,几乎不影响系统其他计算机的工作。(3)灵活性 通过组态软件根据不同的流程应用对象进行软硬件组态,即确定测量与控制信号及相互间连接关系、从控制算法库选择适用的控制规律以及从图形库调用基本图形组成所需的各种监控和报警画面,从而方便地构成所需的控制系统。(4)易于维护 功能单一的小型或微型专用计算机,具有维护简单、方便的特点,当某一局部或某个计算机出现故障时,可以在不影响整个系统运行的情况下在线更换,迅速排除故障。(5)协调性 各工作站之间通过通信网络传送各种数据,整个系统信息共享,协调工作,以完成控制系
13、统的总体功能和优化处理。(6)控制功能齐全 控制算法丰富,集连续控制、顺序控制和批处理控制于一体,可实现串级、前馈、解耦、自适应和预测控制等先进控制,并可方便地加入所需的特殊控制算法。 dcs的构成方式十分灵活,可由专用的管理计算机站、操作员站、工程师站、记录站、现场控制站和数据采集站等组成,也可由通用的服务器、工业控制计算机和可编程控制器构成。 处于底层的过程控制级一般由分散的现场控制站、数据采集站等就地实现数据采集和控制,并通过数据通信网络传送到生产监控级计算机。生产监控级对来自过程控制级的数据进行集中操作管理,如各种优化计算、统计报表、故障诊断、显示报警等。随着计算机技术的发展,dcs可
14、以按照需要与更高性能的计算机设备通过网络连接来实现更高级的集中管理功能,如计划调度、仓储管理、能源管理等。 error! no bookmark name given.dcs 在国内外的发展与应用状态1975 年美国最大的仪表控制公司honeyw ell 首次向世界推出了它的综合分散控制系统tdc2000 ( toal d ist ribu ted con t ro l -2000) , 这一系统的发表, 立即引起美国工业控制界高度评价, 称之为“最鼓舞人心的事件”。世界各国的各大公司也纷纷仿效, 推出了一个又一个集散系统, 从此过程控制进入了集散系统的新时期。在此期间有日本横河公司推出的ce
15、n tum , 美国泰勒仪表公司的mo së , 费雪尔公司的dcé 400, 贝利公司的n 90, 福克斯波罗公司的cpect rum 和德国西门子公司的telepermm。随着计算机特别是微型计算机与网络技术的飞速发展, 加上各制造商的激烈竞争, 使dcs 很快从70 年代的第一代发展到90 年代初的第三代dcs。尽管在这之前的集散系统的技术水平已经很高, 但其中存在着一个最主要的弊病是: 各大公司推出的几十种型号的系统, 几乎都是本公司的专利产品, 每个公司为了保护自身的利益, 采用的都是专利网络, 这就为全厂、全企业的管理带来问题。随着计算机的发
16、展与网络开发使各控制厂商更多地采用商业计算机的技术, 80年代末许多公司推出新一代的集散系统, 其主要特征是新系统的局部网络采用ma p 协议; 引用智能变送器与现场总线结构; 在控制软件上引入plc 的顺序控制与批量控制, 使dcs 也具有plc 的功能。至90 年代初各国知名的dcs 有:3000, bailey 的in f i90,ro semoun t 的rs3, w est hoo se 的wdpf, l eeds &non th rup 的max1000,foxbo ro 的iöa s,日本横河的cen tum。这里所提到的均为大型的dcs, 为了适应市场
17、的需要各厂商也开发了不少中小型的dcs 系统如s9000,max2, lxl ,a 2 pacs 等等。目前国内dcs主要有:新华xdps,鲁能的ln2000,国电智深dcs,中控dcs,和利时dcs,南京科远dcs,浙江中自等。国外的有 西屋(艾默生)ovation、foxboro、abb、西门子pcs7、霍尼韦尔、横河dcs等。 英文翻译dcsdcs distributed control system is the abbreviation of (distributed control system), automation industry in the country is als
18、o known as distributed control system.the so-called distributed control system, or in some of the information in the call distribution system, as opposed to centralized control systems, a new computer control system, which is a centralized control system based on the development, evolution and come.
19、 it is a process by the process control level and the composition of monitoring level communications network as a link to the multi-level computer systems, integrated computer, communication, display and control technologies such as 4c, the basic idea is decentralized control, centralized operations
20、, hierarchical management , flexible configuration, and configuration easy. function in the system, dcs, and centralized control systems are not very different, but in the realization of system functions methods are completely different.first, dcs's skeleton - the system network, which is the fo
21、undation and core dcs. as the network of the system for real-time dcs, reliability and scalability, play a decisive role, so the manufacturers have been careful in this area of design. for the dcs system network, it must meet the requirements of real-time, that is completed within defined time limit
22、s transmission of information. here the word "determine" the time limit is in any case, the information transfer can be completed within this time limit, and this time limit is based on real-time controlled process requirements identified. therefore, indicators of network performance measu
23、rement system is not the network's rate, known as bits per second (bps), but the real-time system network, which can ensure the long period of time to complete the required information transmission . system network also must be very reliable in any case, network communications are not interrupte
24、d, so most manufacturers of dcs were double bus, ring or dual star network topology. scalability to meet the requirements of the system, the system can access the network should be higher than the maximum number of nodes in the large number of nodes actually used several times. in this way, one can
25、always add a new node, it can also make the system run in a lighter network traffic load conditions, to ensure that the system real-time and reliability. during the actual operation of the system, each node of the internet and the net may occur at any time, in particular, operator stations, so that
26、reconfiguration will always be, and this operation must not affect the normal operation, therefore, the system network should have a strong online network reconfiguration functions.secondly, this is a completely on-site i / o processing and realization of direct digital control (ddc) feature of netw
27、ork nodes. to set the general scene in a dcs i / o controllers, to share the entire system i / o and control functions. this site can be avoided due to a failure caused by the failure of the entire system, improve system reliability, the site also allows sharing of data acquisition and control funct
28、ions, will help improve overall system performance. dcs operator station is run operation to deal with all the human-machine interface (hmi-human machine interface, or operator interface) function of network nodes.dcs engineer station is off-line configuration, the system configuration work, and onl
29、ine monitoring, control, maintenance of the network node, and its main function is to provide to the dcs configuration, software configuration tool (ie, the configuration software) and running online in real time dcs dcs network to monitor the operation of each node, the system engineer can engineer
30、 station to adjust the system configuration settings and some system parameters, the dcs at any time under the best working condition. and centralized control systems, are required to have all of the dcs system configuration functions, it can be said, no system configuration functions of the system
31、can not be called as a dcs.dcs since its inception in 1975, has already experienced twenty years of development. in two decades, dcs system architecture although there is no significant change, but through constant development and improvement of its functionality and performance have been a huge inc
32、rease. in general, dcs is toward more open, more standardized product in the direction of development.as the field of process automation computer control system, the traditional dcs is only a narrow concept. if only the production process that dcs automation system, which will lead to wrong conclusi
33、ons, because the meaning of the computer control system has been greatly expanded, and it includes not only the dcs in the past included a variety of content, but also drill down to the each site measuring equipment, implementing agencies, upwards to the production management, all aspects of busines
34、s. traditional dcs now only refers to this part of the production process control automation, and industrial automation system concept, should be targeted to enterprise-wide solution, total solution level. only from this perspective to ask questions and solve problems, to really play the computer au
35、tomation of its role.dcs has the following characteristics:(1) high reliability. dcs system to control the spread of the computer implementation, the system uses fault-tolerant design of the structure, so a computer system malfunction will not cause the loss of other functions. in addition, each com
36、puter system, the tasks undertaken by relatively simple functions can be used for the need to achieve a specific structure and special computer software, so that the reliability of each computer system has also been improved.(2) open. dcs an open, standardized, modular and serial design, the system
37、means each computer using the lan communication, to achieve information transmission, when the need to change or expand the system functionality can be added easily connected to a computer system communication network or remove from the network, almost does not affect the work of other computer syst
38、ems.history of development of dcsdcs distributed control system is the abbreviation of (distributed control system), automation industry in the country is also known as distributed control system.it is a process by the process control level and the composition of monitoring level communications netw
39、ork as a link to the multi-level computer systems, integrated computer (computer), communication (communication), display (crt) and control (control) and other 4c technology, the basic idea is decentralized control, centralized operations, hierarchical management, flexible configuration, easy config
40、uration. )its development can be divided into three stages.stage :1975-1980, during this period the technical characteristics of distributed control system as follows:1) using microprocessor-based control unit, to achieve decentralized control, a wide variety of algorithms, through the loop control
41、configuration independently, with self-diagnostic function2) the operating station with a crt display unit and the process of separation, centralized monitoring, centralized operation3) a more advanced communication system redundancythe second phase :1980-1985., distributed control system during thi
42、s period the technical features as follows:1) increase the number of bits microprocessors, crt display resolution to improve2) strengthening the modular system3) strengthen the system of information management, strengthening communicationthe third phase, after 1985, the third generation of distribut
43、ed systems, and its technical characteristics were as follows:1) the adoption of open systems management2) 32-bit microprocessor operating station3) using real-time multi-user multi-tasking operating systeminto the next decade, computer technology advances, more new technology is being applied to th
44、e dcs. plc is a sequential logic control developed for electronic equipment, which is used instead of inflexible and cumbersome relay logic. fieldbus technology in entering developed very rapidly since the mid nineties that some people have to predict: fcs based on field bus control system will repl
45、ace the dcs as the protagonist.dcs is a data communication subsystem (data communications subsystems) for short.to rail transportation industry, for example, dcs is a pure non-transparent security system, he is sent between the control center and train carrier packet.dcs second layer of meaning: dor
46、sal column stimulator medical spine stimulatorin the special control areas, such as nuclear power plant control system, dcs is the meaning of digital control system (digital control system).dcs main domestic manufacturers are: shanghai xinhua, the super control, state power zhishen, zhejiang univers
47、ity in control, and belgium, shanghai chinese, shanghai leroy, from zhejiang and so on. there westinghouse abroad (emerson), foxboro, abb, siemens, honeywell, yokogawa, yamatake - honeywell, fisher-rosemount companiesoverview of characteristics and development of dcsdcs is a distributed control syst
48、em (distributed control system) for short, is commonly called the domestic general distributed control system. it is a process by the process control level and the composition of monitoring level communications network as a link to the multi-level computer systems, integrated computer (computer), co
49、mmunication (communication), display (crt) and control (control) technologies such as 4c, the the basic idea is decentralized control, centralized operations, hierarchical management, flexible configuration, easy configuration.dcs has the following characteristics:(1) high reliability of the dcs sys
50、tem to control the spread of the computer implementation, the system uses fault-tolerant design of the structure, so a computer system malfunction will not cause the loss of other functions. in addition, each computer system, the tasks undertaken by relatively simple functions can be used for the ne
51、ed to achieve a specific structure and special computer software, so that the reliability of each computer system has also been improved.(2) dcs open an open, standardized, modular and serial design, the system uses the computer local area network communication means to achieve information transmiss
52、ion, when the need to change or expand the system functionality can be added easily with a computer communication network into the system or removed from the network, almost does not affect the work of other computer systems.(3) flexibility in the configuration software through the process of applic
53、ation objects according to different hardware and software configuration, which determine the measurement and control signals and inter-connection of the control algorithms from the library and select the appropriate control law called from the basic graphic components graphic library required for v
54、arious monitoring and alarm screen, thus easily constitute the required control system.(4) easy maintenance features a single small or micro-dedicated computer, with easy maintenance, convenient features, and when a local or a computer failure, you can run the system without affecting the case of li
55、ne replacement, rapid troubleshooting .(5) coordination between the various stations of various data transmission through the communication network, the whole system of information sharing, coordination of work to complete the control system's overall functionality and optimization.(6) control f
56、unctional control algorithm rich set of continuous control, sequence control and batch control in one, can be realized cascade, feedforward, decoupling, adaptive and predictive control, advanced control, and easily add the necessary special control algorithms. the composition of dcs approach is flex
57、ible, managed by a dedicated computer stations, operator stations, engineering stations, recording station, site controller and data acquisition stations and other components, but also by a common server, industrial computer and programmable controller was. at the bottom of the process control level
58、 are generally distributed on-site controllers, data acquisition stations, data acquisition and control in place, and through the data communications network to monitor and control level computer. production control level on the data from the process control level centralized operations management,
59、such as various optimization, statistical reports, fault diagnosis, alarm and so on. with the development of computer technology, dcs can follow a more high-performance needs and computer equipment connected through the network to achieve more advanced centralized management features, such as planning and scheduling, warehouse management, energy management.dcs in the development and
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