Field Data Monitoring Technology Based On Device Description

Fieldbus control system has been widely used in areas of industrial production, at the same time better functions are required in monitoring system status and field data. Field device integration and the management of field data are the key point to realize better monitoring.The content of this study mainly includes field device integration, real-time data management and the software design of data exchanging platform. Firstly the functions of device descriptioon are discussed, and device resources of PEC8000 are analyzed. Based on these it gives out device description based on XML, which includes device basic information, device parameter, storage area, variable and protocol, and PEC8000 description file is developed.According to thearies of real-time database, real-time data management model based on variable mapping is proposed, in which field data and its relative operations are managed as different kinds of variables.Memory data are stored in table set, and data index is set up by hash table. The software design of data exchanging platform includes user interface, description parsing, project management, communication compile and running system. Different device description files are parsed by DOM, and field devices are integrated to the platform through device description. System configuration information are managed in a project, by which data platform could adapt various control systems and the need of data management with good flexibility. Communication compiling is used in communication content grouping and message making. In running system tasks are managed by classification, and concurrency control is realized by self-locking. Communication scheduling is finished based on communication group which is produced by communication compiling, and device driver is realized by multiple thread technology, data service interfaces are used to afford field data or relative event to monitoring application. Finally the functions of data platform are testified, and the moduls of the platform could realize their functions.