随着工业测控技术和生产自动化技术的不断进步 ,传统的 RS-232、 RS-485和 CCITTV. 24通信技术已不能适应现代化的工业控制需要 ,而现场总线 ( Fieldbus)以其低廉的价格、可靠的性能而逐步成为新型的工业测控领域的通信技术。现场总线是应用在生产现场 ,在微机化测量控制设备之间实现双向串行多节点数字通信的系统 ,是一种开放式、数字化、多点通信的底层控制网络。 汇集了计算机技术、网络通信技术和自动控制技术 ( 3C)的现场总线技术 ,从 20世纪 80年代开始发展起来 ,并逐步在制造业、流程工业、交通、楼宇等方面的自动化系统中得到了广泛的重视和应用。现场总线主要有以下几种类型 : 基金会现场总线 ( FF)、 LonWorks、 ProfiBus、 CAN、HART,而其中 CAN ( Controller Area Network)即控制器局域网因为具有高性能、高可靠性以及独特的设计而越来越受到关注,现已形成国际标准 ,被公认为几种最有前途的现场总线之一。- With the continuous progress of industrial measurement and control technology and automation technology, the traditional RS-232, RS-485 and CCITTV. 24 communications already can not adapt to the needs of modern industrial control, and Fieldbus to its low price and reliable performance gradually become communication technology of the new type of industrial control field. Fieldbus is a kind of system which is used in the production field. It is an open, digital and multi point communication system. It is an open, digital and multi node communication system. A collection of computer technology, network communication technology and automatic control technology (3C) of the fieldbus technology,　the 80s of the 20th century began to development, and gradually in manufacturing industry, process industry, transportation, buildings, and other automation system has been widely recognized and applied. Field bus is mainly has the following several types: the foundation fieldbus (FF), LonWorks, PRO