基于RS485物理层的MODBus/JBus现场总线通信协议

Field-bus communication protocol of JBus/MODBus based on RS485

本文描述了在现场总线控制系统中,按照基于RS485物理层的MODBus/JBus现场总线通信协议,采用主机/从机原理和远程终端单元(RTU)模式,实现主机和从机之间的数据通信,通过对从机上相应的内存单元的读写来适时获取和改变设备参数,以实现工业自动化系统中对设备的适时控制。并通过实验完成了与德国JUMO公司开发的紧凑型微处理控制器dTRON04.1的通信,验证了该协议的可行性和可靠性。

This paper presented a way to carry out the communication between a PC （master） and an instrument （dave） using MODbus/Jbus based on RS485 in the FCS （Field-bus control system）. The communication based on the master-slave principle and the transfer mode of Remote Terminal Unit （RTU）. By reading or writing the appropriate memory unit in the dave＇s EEPROM, it can obtain or change the parameters. So it can carry out the real time control of the immanent in automation control system in industry.Also the feasibility and reliability of the protocol is validated by experiment of communicating with the compact microprocessor controller dTRON04.1.