基于单片机的多变频器Modbus通讯控制

Microcontroller-based Modbus Communication Control of Multiple Inverters

为解决变频器与同品牌PLC通讯往往采用专用协议,不利于不同品牌的多变频器的通讯控制的问题,提出一种以单片机控制板代替PLC或工控机作为控制核心,以高性价比的串口屏作为人机界面,实现不同品牌的多变频器的Modbus通讯控制方案。所设计的单片机控制板带有RS485接口电路,具备IO控制功能,分析了变频器Modbus通讯协议的硬件接线、寄存器设置、Modbus帧,设计了单片机Modbus主站程序,通过串口屏实现人机交互,完成对不同品牌变频器的通讯控制。实际应用表明,提出的方案极大地降低了成本,提高了通用性和可移植性,具有较大的实用价值。

In order to solve the problem that communication between inverter and PLC of the same brand often adopts special protocol, which is not conducive to the communication control of multiple inverters of different brands, a Modbus communication control scheme for multiple inverters of different brands was proposed with a microcontroller control board instead of PLC or industrial control machine as the control core and a cost-effective USART HMI as the human-machine interface. The designed board with RS485 interface circuit had IO control function,the hardware wiring, register setting and Modbus frames of Modbus communication protocol of inverter were analyzed, the Modbus master program was designed, the communication control of different brands of inverters was completed through the USART HMI. Practice shows that the program greatly reduces costs, improves versatility and portability, and has greater practical value.