Control of AC Motor through VFD with Modbus communication via Labview

[Alexis_Koul]

Hello,

I start working on it again yesterday. I used a Modbus software( Commix) and the VFD was working perfectly. Now I an working on the VFD and this is my current stage. Still is not working..

In the other software, what I was using was only the hexadecimal code from page 128 as you said and it was working. In labview I still dint use those codes because I can add the upper part which is the hexadecimal, but I dont know what to put in the lower part ..

[Alexis_Koul]

Hello,

I start working on it again yesterday. I used a Modbus software(Commix) and the VFD was working perfectly. Now I an working on the VFD and this is my current stage. Still is not working..

In the other software, what I was using was only the hexadecimal code from page 128 and so on,  it was working. In labview I still dint use those codes because I can add the upper part which is the hexadecimal, but I dont know what to put in the lower part ..

I am attaching also the link of the VFD manual: http://www.gozuk.com/download/GK-3000-Variable-Frequency-Drive-User-Manual.pdf

Any help is highly appreciated. 

-Alex

[GerdW]

Hi Alex,

please keep related things in one place instead of starting new threads for the same problem!

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@Alexis_Koul wrote:

In labview I still dint use those codes because I can add the upper part which is the hexadecimal, but I dont know what to put in the lower part ..

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What is "upper part" and what is "lower part"?

How are those "parts" related to hexadecimal display of numbers?

[Alexis_Koul]

Hello GerdW,

As you can see in the photo that I attached, every write single holding registers have the address and input data, as I have understood. The address is on hexadecimal but the input data is decimal.

As I said also, with Commix is working perfectly..but I cant make it work in LAbview..

For example in commix I am inputing the following

01 06 20 01 00 02 which is if you go to page 134 and  135. Address: 01H, Commands to VFD: 06H, Parameter Address: 2001H and Function Description: 0002H

How I do the same with the Labview? Noone of those I have used..

[GerdW]

Hi Alex,

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@Alexis_Koul wrote:

01 06 20 01 00 02 which is if you go to page 134 and  135. Address: 01H, Commands to VFD: 06H, Parameter Address: 2001H and Function Description: 0002H

How I do the same with the Labview? Noone of those I have used..

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You need to provide the address (×2001) and the value (×0002) to a ModbusWrite function…

The address is already provided in the ModbusInit function ("unit"), the command is selected by using the correct ModbusWrite function (write holding register).

Read the help of this Modbus library to learn if/how this encodes the "write holding register" command - I never used those libraries as I created the Modbus messages on my own, using plain VISA functions for communication.

[Alexis_Koul]

Hello,

Based on your feedback, I Changed the VI as the photo attached. Unfortunately still the motor doesn't run.

Not sure what I still have to changed. Looks that I am getting closer, but still...

[GerdW]

Hi Alex,

can you show the context help of this ModbusWrite function?

Why are the constants holding the parameter value labelled "unit"?

[Alexis_Koul]

Hello,

Thank you for your quick reply.

For question 1:

For question 2: I wrote them like this..

Looking forward to your reply,

Thank again.

Alexis

[Alexis_Koul]

Hello,

Any thoughts regarding my last comment?

Alex

[Alexis_Koul]

Finally IT WORKS!!