摘要
基于HART协议的现场仪表已普遍使用,这些仪表主要是通过传统的RS-232接口实现同上位机之间的通信。基于FT8U232BM芯片开发的USB-HART通信接口,以其传输速度快、占用资源少以及真正意义上的即插即用等优点,正在逐步取代RS-232接口。详细叙述了USB/RS-232双向转换芯片FT8U232BM以及Hart调出解调器芯片A5191的工作原理、内部结构、引脚分布及功能,并给出了利用此二者实现的USB/HART通信接口典型电路设计方案和驱动软件。实践证明它是一种经济高效的设计方案。
Most of the HART protocol, based field instruments have been popularly used. These instruments are communicated with host computer through traditional RS-232 interface. The USB-HART communication interface developed based on FT8U232BM chip replaces RS-232 interface. It features fast speed to transmit, using less resource and plug-and-play. The principle of operation, internal structure, pin designation and functions of USB/RS-232 bi-directional conversion chip FT8U232BM and A519 are described in detail. Design strategy of typical circuit and drive software of USB/HART communication interface composed of above two chips is provided. The practice proves that it is an economical and highly efficient design strategy.
出处
《自动化仪表》
CAS
2006年第5期17-20,共4页
Process Automation Instrumentation
关键词
驱动软件
即插即用
虚拟串口
Drive software Plug-and-play Virtual serial port
