Reading data using Modbus RTU

[bestecf]

Hi friends,

I have a temperature display which is ORDEL PC771. You can click for datasheet. Datasheet is not English. Communication protocol is MODBUS RTU over RS435. 

There is a device between computer and ORDEL which is ATEN UC2324 4-Port USB to RS-232 Hub.  

I want to communicate with ORDEL to read and display temperature data on Labview. You can examine a file attached. However, connection is not provided. There is no data from ORDEL.

Thanks for your comments.

[RavensFan]

Your VI doesn't really do anything really to Modbus RTU.  Just grabs bytes received on the serial port.

If you search NI.com for modbus, you'll see several libraries that include examples.

[bestecf]

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@RavensFan wrote:

Your VI doesn't really do anything really to Modbus RTU.  Just grabs bytes received on the serial port.

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Yes, it's to read serial port. Temperature data is sending over RS435 to "4-Port USB to RS-232 Hub", then connecting with USB to computer. So, I did this .vi

[RavensFan]

But your VI doesn't do modbus.

If you want Modbus, then download a modbus library.  Look in JKI VI Package Manager.  Look at the example.

I think newer LabVIEW versions have a modbus library built in under the Data Communication palette.

[GerdW]

Hi bestecf,

why do you ask by PM when you already got valuable help by RavensFan?

Just do as suggested: use one of those available MODBus libraries to communicate with your device…

[bestecf]

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@RavensFan wrote:

But your VI doesn't do modbus.

If you want Modbus, then download a modbus library.  Look in JKI VI Package Manager.  Look at the example.

I think newer LabVIEW versions have a modbus library built in under the Data Communication palette.

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RavensFan thank you. I'm going to examine file I have attached. I guess that i should focus  title of "MB Serial"

[bestecf]

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@GerdW wrote:

Hi bestecf,

why do you ask by PM when you already got valuable help by RavensFan?

Just do as suggested: use one of those available MODBus libraries to communicate with your device…

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Sorry GerdW, thanks..

[RavensFan]

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@bestecf wrote:

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@RavensFan wrote:

But your VI doesn't do modbus.

If you want Modbus, then download a modbus library.  Look in JKI VI Package Manager.  Look at the example.

I think newer LabVIEW versions have a modbus library built in under the Data Communication palette.

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RavensFan thank you. I'm going to examine file I have attached. I guess that i should focus  title of "MB Serial"

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That is a pretty good library.  I've used it for years without any problems.   Yes.  Look at MB Serial Example Master.vi.

[bestecf]

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@RavensFan wrote:

  Look at MB Serial Example Master.vi.

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I run MB Serial Example Slave.vi before Master.vi. But there is no change front panel in Master vi. 

[bestecf]

I want to share a connection that I previously forgot to add.