【摘要】 设计了一种基于４～２０ｍＡ标准的智能仪表．采用较为通用的硬件设计出低功耗系统以满足４～２０ｍＡ模拟标准，同时又满足数字信息传输的要求．介绍了系统的工作流程及通信模块设计．更多还原

【Abstract】 An intellignt instrument based on 4~20 mA standard is (下转第５５页）designed in which is implemented by adoption of a hardware in common use so as tomeet the demands of a low power consumption system and digital signal transmission.Also, the physical layer and data link layer protocols, and the communication modulesare introduced.更多还原