基于opc的实时数据库的设计与实现（Design and implementation of real time database based on OPC）.docVIP

基于opc的实时数据库的设计与实现（Design and implementation of real time database based on OPC） Research and design of component based distributed real-time monitoring platform Qing Lei Zeng [Abstract] this paper presents a component based distributed monitoring system platform based on OPC interface, and discusses the interface implementation of each part of the system. The platform consists of a set of software components, fault tolerance, self adaptive interface open a package for each component of intelligent software entities with independent function, time cognition, communication between the various components quickly and efficiently through the priority message queue, which can provide real-time data acquisition, storage and access functions and Web services on the whole. Finally, this paper discusses the process of client browser using data publish / subscribe mode to access real-time and historical data using SOAP messages. Key words: distributed monitoring system, OPC, XML 1 Introduction In many real world applications system includes real-time access and management of large amount of field data, such as factory production process monitoring, dispatching, building automation and so on, the system must be able to get the real-time data from the controlled environment, in order to understand the latest state control site at any time, and combined with the past data to respond to and when. Among them, the data processed are often transient and are called temporal data, while the expired temporal data is often called historical data. The validity of temporal data maintenance is an important part of temporal data management, and the temporal consistency requirement of data can lead to the temporal restriction of transaction [1]. Real-time database is a database whose data and transactions have time constraints. The correctness of the system depends not only on the result of the transaction, but also on the time it takes. RTDB architecture, transaction scheduling, concurrency