Appearance and application of fieldbus control technology is base on smart instruments . this paper design a applied circuit of hart protocol smart instrument on which mainly discusses and analyze importance and difficulty of hart protocol 本文的目的是在详细讨论、分析hart协议智能仪表的设计重点、难点和技术关键的基础上，设计完整的hart协议智能现场通信器的实用电路。
By a practical engineering , this paper is about research & design job of industrial field lans based on the siamtic sinec , siemens corp . the author constructed a rudiment of pcs , which was the abbreviation for fieldbus control system , by using fieldbus technology , and accomplished the data communication between operating stations and field equipments 本文主要的工作是通过一个实际的项目，进行了基于西门子公司simaticsinec工业现场通信网络的研究与设计。作者采用目前日益流行的现场总线技术，构建了新一代fcs (现场总线控制系统)的雏形，实现了现场设备和操作站之间的数据交换，为企业建设cims乃至企业全面的信息化打下了坚实的基础。
At present time , there are some primary shortages in distributed computer monitoring system : due to different communication protocols used in monitoring system , which brings on difficulties when we integrate system ; the application software of monitoring system is poor in interoperability and reusability ; the isomeric characters of net in computer monitoring make it hard to integrate system 目前分布式计算机监控系统存在的主要问题包括：系统中由于现场设备的通信协议以及现场通信网络的差异而导致系统难以集成；监控系统的应用软件的互操作性差、可重用性不强；以及监控系统中网络异构等问题。
According to the standard of can agreement the message agreement for the system has been designed . whose design thinking and its realizing way of the three kernel parts ( can kard ^ can oriented object and field communicatioan interface moudule ) in the system have been given . it is applied by the oriented subject technigue , and through the analyses of ststic characteristic , and dynamic characteristic of the equipment , the configuration tool category has been gotten to complete the configuration to equipment 系统通过传输介质把监控中心和现场通信接口模块挂接在can总线上，组成一个控制器局域网络，从而实现对各种在线通信电源设备的分散控制、统一管理；根据can协议的规范设计了系统的通信协议，给出了系统中三大核心部分( can适配卡、 can中继器和现场通信接口模块)的设计思路和实现方式，并给出了相关硬件电路的结构框图以及软件设计流程图；运用面向对象技术，通过对设备的静态特征和动态特征的分析，得到其组态工具- -类，完成对设备的组态。
