Research On Embedded Industry Control System Based On Fieldbus

As the development of the electronic technology, Fieldbus-Control-System becomes the mainstream architecture of industry controlling network. The Industry control system based on DSP is characteristic of more precision and more processing speed. The integrating of DSP and Fieldbus brings a new thought of industry control technology.In this article, the characteristics of various Fieldbus are compared, and the proper Fieldbus Controller Area Network Fieldbus (CAN bus) is selected. An industry controlling network system based on TMS320F2812 Digital Signal Processor and CAN bus is researched. This system contains master and slave. Master communicates with the PC server using Ethernet, and controls tens of slaves using CAN bus, and displays the parameters of slaves on its Electroluminescent (EL) Display realtime.In Communication, the TCP/IP protocol stack is modified. Only the needed module is preserved, to reduce the code size and speed up the process.In the field of EL Display, an EL Display Controller is implemented using the Verilog Hardware Description Language on a Complex Programmable Logic Device (CPLD). The EL control logic and an unique bidirectional bus isolator is contained in the CPLD, so that the main processor and EL controller can share the display buffer, and the EL controller accessing the display buffer don't need to use the processor's external bus. The display refresh frequency is up to 64.5Hz.In software, two masters hot stand-by is implemented using the CAN bus. Normally, one master work and the other is in stand-by mode. If the working one is error, the stand-by one will relay immediately to achieve high reliability.In User Interface, a friendly Graphic User Interface (GUI) with touch screen is implemented. In order to develop easily, two PC auxiliary programs are designed, one is Image Lattice Maker, and the other is EL Simulator. The Image Lattice Maker can generate compressed format source code from picture, and the EL Simulator can simulate the GUI on PC with a cross-platform low level function library, to speed up the program development.