免加密狗西门子CP341模块的Modbus RTU通信实现

Realization of Modbus RTU Communication on Siemens CP341 Module without Dongle

介绍了西门子CP341模块和Modbus通信协议,详细讨论了Modbus RTU模式的循环冗余校验(CRC)码的实现,以CP341模块作主站,采用多点轮询方式,基于其免费支持的ASCII驱动协议,编程实现与三菱F700变频器从站的Modbus RTU通信。结果表明,该方法通信可靠、成本低廉、使用方便,具有广泛的应用价值。

Siemens CP341 Module and Modbus protocol are introduced. Realization of the CRC （Cyclic Redundancy Checks） with the Modbus RTU is discussed in detail. By Multi-Station Polling, programmed in the master station of CP341 based on its integrated ASCII driver, the Modbus RTU communication with the slivery station of the Mitsubishi F700 inverter is implemented. The running result shows that this method is characterized by reliable communications, lower cost, convenient utilization, and wide application.