Integration Design And Test Of Heterogeneous Filed Bus System And Device

Because of diversity of fieldbus type, a great of diversity of products are provided for customers. But meanwhile, it also bring to customers compatibility problems among different systems or devices. There is no field bus can be fully applied to all the scope of application, but there is some intersection application scope among different field buses, which resulted in a variety of field buses exist in same system. Plant expansion, renovation and other processes are likely to choose the fieldbus system or devices with different standard from the original system,so data sharing among them can not be achieved. With the deep development and widely adopt of filedbus, more and more customers demands that integrate kinds of fieldbus systems into single system. Control system integration is designed to allow different control systems and field devices from different manufacturers to be integrated for working together smoothly according to a specific application goal.. At present, there is two main methods can realize the integration of heterogeneous. First, the OPC technology can be used for control system level integration. The second, fieldbus controller can realize the device-level integration with single chip. OPC (OLE for process control) standard based on Microsoft's COM specification, which defines general interface among hardware, software and system from different manufacturers. This makes diversity of hardware, software and system in process control system and plant automation connect, communicate and operate each other. And OPC can be a good solution to data communication problems among heterogeneous fieldbus systems. Heterogeneous fieldbus control systems integration and configuration is more simple with adoption of OPC technology, but all data shall be collected and handled through software database, and data work is dependent on the software, therefore data transmission and processing speed is slow, only for enterprise production management, optimal control, scheduling decision-making support which have limited real-time requirement. Single chip with fieldbus protocol controller chip integrates fieldbus controller, single chip, dual-port memory and ISA interfaces, and connected to the work station ISA slot. Single chip is in charge of data transmission and reception, and fieldbus controller is in charge of data collection and conversion, meanwhile system configuration software is in charge of data processing, control and management. This not only makes control system and fieldbus devices communicate each other effective and integrates systems and field device smoothly, but also solve the low data transfer rate and poor reliability of data transmission problems. It can achieve the goal of real-time, reliability requirements for production process control. Fieldbus controller integrates method need to design the circuit of single chip, fieldbus controller, dual-port, and also need to design corresponding program for specific work station and fieldbus controller, including hardware initialization program, data collection procedures program etc. These two integration method were separately studied and tested in bio-diesel plant in Bayer integrated site Shanghai.