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Mitsubishi FX5U “Modbus RTU” Danfoss FC302 Tutorial

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Hello everyone, PLC Mitsubishi FX5U is a new generation PLC integrated with many modern features such as Ethernet, RS485, Analog communication ports… And it also integrates Modbus-RTU Communication Method

Today will guide you to use FX5U to control Danfoss FC302 via Modbus-RTU (Danfoss FC302 inverter also has built-in RS485 port)

Mitsubishi FX5U & Danfoss FC302 “Wiring Diagram”

Note: If the communication distance is longer than 20m, a 120Ω terminal resistor should be used

Danfoss FC302 Modbus-RTU Configuration

In addition to the basic parameters of the inverter (Frequency, current, voltage…) then we need to set the communication parameters as the table below to be able to control Danfoss FC302 with Modbus RTU

Danfoss FC302 Register for Control

>>> VFD Control Command = C34F (hex)

+ Set Word C34F = 47C (hex) >>> Run Forward
= 847C (hex) >>> Run Reverse
+ Set Word C34F = 43C (hex) >>> Stop
+ Set Word C34F = 4BC (hex) >>> VFD Reset

>>> Speed Reference Address = C359 (hex)
+ Speed Reference = 0 to 16384(dec) ~ (0 to 100%)

Danfoss FC302 Registers for Monitoring
Note: Danfoss FC302 Address = “(Table Address*10) – 1

+ Voltage Output Address = 16119 (dec)
+ Frequency Output Address = 16129 (dec)
+ Current Output Address = 16139 (dec)
+ Speed Output Address = 16169 (dec)

Mitsubishi FX5U Modbus RTU Setting

We need to configure Modbus communication parameters in PLC same as Danfoss FC302

FX5U PLC Programming

+ Read / Write Distribution

+ Speed Setting Command

+ VFD Control Run

+ Read Data Response

Detailed Instruction Video


Related Software and Documents

>>> Download GX Works3 Mitsubishi Software
>>> Download Danfoss FC302 Manual PDF

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If you have any problems in the process of connecting PLC FX5U with Danfoss FC302 VFD, please comment below the article, will reply to you as soon as I read your comments.

Best Regards!

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  • Buenos días, disculpa la molestia, estoy batallando con la conexión del puerto RS-485 de la HMI GS2107-WTBD-N de mitsubishi, la estoy tratando de comunicar con el PLC FX5U para el control de un variador Danfoss pero no logro establecer bien la cominicación

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