基于嵌入式的现场总线和TCP/IP协议转换的技术研究

摘要

通过对企业控制网络和信息网络互联的研究,以期实现数据在控制网络和信息网络之间的传输.企业控制网络基于现场总线,采用现场总线协议.而企业信息网络基于工业以太网,采用TCP/IP 协议.因此,控制网络和信息网络的集成就转为现场总线协议和TCP/IP协议的转换.由于现场总线的多样性,着重研究现场总线中使用广泛的RS 232,RS 485,CAN总线协议,采用32位AT91RM9200微处理器的嵌入式系统具有处理速度快、体积小、性能稳定等特点,是嵌入式网关硬件平台的首选.建立了协议转换的网络层次模型,设计了软硬件平台,实现了现场总线协议和TCP/IP 协议的转换,测试了协议转换的运行情况,实现了RS 232,RS 485,CAN总线协议和TCP/IP协议的数据双向传输,可以应用于工业生产、家庭网关、远程监控等领域.%The interconnection of enterprise control network and information network is researched to transmit the data be-tween control network and information network. The fieldbus protocol is adopted by enterprise control network which is based on fieldbus,and the TCP/IP protocol is adopted by information network which is based on industrial Ethernet,so the integration of the two networks is turned to the conversion between fieldbus protocol and TCP/IP protocol. Considering the diversity of the field-bus,the RS 232,RS 485 and CAN bus protocols widely used in fieldbus are studied emphatically. The embedded system with a 32-bit microprocessor AT91RM9200 has the characteristics of high speed processing,small size and steady performance,and is the preferred selection to the hardware platform of the embedded gateway. The network layer model of protocol conversion was established,the hardware and the software platforms were designed to realize the conversion between fieldbus protocol and TCP/IP protocol. The running condition of the protocol conversion was tested to implement the two-way data transmission between fieldbus(RS 232,RS 485,CAN bus)protocol and TCP/IP protocol. The system can be applied in the fields of industrial pro-duction,home gateway and remote control.