本文介紹了Modbus RTU 通信協(xié)議在變頻調速系統(tǒng)中的應用，采用基于RS485 接口的
Modbus RTU 通信協(xié)議，實現(xiàn)PLC和各變頻器之間的串行通訊，通過變頻器對交流電進行變頻調速。結果表明，該方法極大地減少線路連接的復雜性，提高了系統(tǒng)的抗干擾能力。
關鍵詞: Modbus RTU 協(xié)議；RS-485；變頻調速；

Abstract:This paper introduces the application of Modbus RTU Protocol in variable frequency speed regulation system.The serial communication between PLC and frequency-converters is realized based on the Modbus RTU protocol of the RS485 interface and makes variable-frequency speed regulation control for AC motor.The experiment results showed that this control mothod greatly reduced the complexity of the circuit conjunction and improved the performance of disturbance rejection of the system.
Key words：Modbus RTU Protocol；RS-485；variable frequency adjusting speed；