MCGS在PLC工作状态监控系统中的应用

1、MCGS组态软件在PLC工作状态监控系统中的应用可编程控制器( PLC) 自问世以来, 以其可靠性高、通用性强等优点, 广泛应用于工业自动化的各个领域。在使用PLC 对各种制造装备、自动化生产线等进行控制时, 必须对各类故障做出实时正确的反应; 若发生意外, 应及时处理。因此, 为提高控制系统的整体效益, 需要对PLC 工作状态监控功能提出一定的要求。目前, 常用的PLC 工作状态监控方式主要有两种。一种是利用与PLC 配套的编程软件所具有的监控功能, 当PLC 工作在监控方式时, 在上位机的监控界面中, 以PLC 程序语句闪烁等形式表示故障报警, 监控者需要根据PLC 程序内容推测故障环节,

2、 再予以排除。其技术要求高, 现场工作有较大的困难。另一种方法是用VC+、VB 等程序设计语言编制监控程序软件包, 在上位机中以直观的图形界面显示PLC 及被控对象的工作运行状态, 从而能够形象显示故障环节。但其软件设计工作难度高, 编程量大, 开发周期长。考虑到上述两种方法的不足, 以MCGS 工控组态软件为开发平台, 通过相对容易的组态编程工作, 较好实现可编程控制器工作状态监控的功能。现场总线技术是20世纪80年代后期发展起来的一种基于现场设备之间进行通讯的新型总线系统，它综合了数字通信技术、计算机技术、自动控制技术、网络技术和智能仪表等多种技术手段，从根本上突破了传统的“点对点”式的模

3、拟信号或数字一模拟信号控制的局限性，构成一种全分散、全数字化、智能、双向、互连、多变量、多节点的通信与控制系统。现场总线则是连接智能现场设备和自动化系统的数字式、双向传输、多分支结构的通信网络，其基础是智能仪表。分散在各个工业现场的智能仪表通过数字现场总线连为一体，并与控制室中的控制器和和监视器一起构成现场总线控制系统(Field Bus Control System, FCS)。通过遵循一定的国际标准，可以将不同厂商的现场总线产品集成在同一套FCS中，具有互换性和互操作性。FCS把传统DCS的控制功能进一步下放到现场智能仪表，由现场智能仪表完成数据采集、数据处理、控制运算和数据输出等功能。现

4、场仪表的数据(包括采集的数据和诊断数据)通过现场总线传送到控制室的控制设备上，控制室的控制设备用来监视各个现场仪表的运行状态，保存智能仪表上传的数据，同时完成少量现场仪表无法完成的高级控制功能。另外，FCS还可以通过网关和企业的上级管理网络相连，以便管理者掌握第一手资料，为决策提供依据。所以现场总线具有开放性、互操作性、系统结构的高度分散性、灵活的网络拓扑结构、现场设备的高度智能化、对环境的高度适应性等诸多突出特点。尽管目前对现场总线的研究尚未能形成一个完善的统一标准，但现场总线的高性能价格比将吸引众多工业控制系统采用。Work in the PLC configuration softwar

5、e MCGS Condition Monitoring System Programmable Logic Controller (PLC) since inception, with its high reliability, high universality, it is widely used in industrial automation fields. The use of PLC for various manufacturing equipment, automated production lines, and control must be made on all kin

6、ds of real-time fault right response; if an accident should be a timely manner. Therefore, in order to improve the overall effectiveness of control systems need to work on the PLC to make certain state monitoring requirements. At present, the commonly used condition monitoring PLC work There are two

7、 ways. One is the use of matching with the PLC programming software with the monitoring function, when the PLC work in monitoring mode, monitoring the PC interface to flash the form of PLC program statement that failure alarm, monitor the content of those procedures need to PLC speculated that failu

8、re link, and then be excluded. The technical requirements for high on-site work more difficult. Another method is to use VC + +, VB and other programming languages monitor program package preparation, the host computer in an intuitive graphical interface displays the work of the PLC and the plant is

9、 running, which can link the image display failure. However, the high degree of difficulty of its software design, programming capacity, long development cycle. Taking into account the above two methods, with a view MCGS Configuration Software as the platform to a relatively easy configuration throu

10、gh programming, programmable logic controller to achieve better working condition monitoring functions. Fieldbus technology is the 20th century, developed in the late 80s as a communication between field devices based on the new bus system, which combines digital communications technology, computer

11、technology, automation technology, network technology and intelligent instruments and other technical means , a fundamental breakthrough in the traditional point to point of the analog signal or digital an analog signal control limitations, constitute a fully distributed, fully digital, intelligent,

12、 two-way, interconnect, multi-variable, multi-node communication and control system. Fieldbus intelligent field devices are connected and digital automation system, two-way transmission, multi-branch structure of the communications network, based on smart meters. Scattered in various industrial fiel

13、d by digital field bus intelligent instruments as a single entity, and with the control room and monitor the controller and together constitute the field bus control system (Field Bus Control System, FCS). By following certain international standards, different vendors can be integrated fieldbus pro

14、ducts in the same set of FCS with interchangeability, and interoperability. FCS control of the traditional DCS function further into the site under the intelligent instrument, intelligent instrument completed by the on-site data collection, data processing, control algorithms, and data output functi

15、on. Field instrument data (including collection of data and diagnostic data) sent to the control room through the field bus control device, the control room control equipment used to monitor the operational status of each field instrument, preservation intelligent instrument upload data simultaneous

16、ly small field instrument can not be completed advanced control functions. In addition, FCS can also be superior gateway and enterprise management network connected to management first-hand information, provide the basis for the decision. Therefore, the fieldbus is open, interoperability, system architecture, a highly decentralized, flexible network topology, on-site equipment, highly intelligent,