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LabVIEW MODBUS16 communication

Hello,

Does anyone have a good example of how to communicate with the following protocol via RS232 MODBUS16 CRC?

  • Baud Rate: 19,200
  • Data bits: 8 Bits
  • Parity: None
  • Stop Bit: 1
  • CRC: MODBUS16

 

Thanks,

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Message 1 of 8
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Modbus16 - I don't know about such a protocol.

 

There are several LabVIEW libraries available for download that are capable of

Modbus ASCII, Modbus RTU and Modbus TCP.

 

All of these include examples.

 

Regards, Jens

Kudos are welcome...
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Message 2 of 8
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Thanks for the information.  Where can I find the libraries?

 

Thanks,

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Easiest way is the VI Package Manager https://vipm.jki.net/

 

If you don't use that just do a search for "LabVIEW Modbus".

LabVIEW Pro Dev & Measurement Studio Pro (VS Pro) 2019 - Unfortunately now moving back to C#, .NET, Python due to forced change to subscription model by NI. 8^{
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I was able to install the libraries, however, how can I send the following command to a device?  None of the functions have a data send input.

0xA5 0x05 0x0D CRC

 

Thanks,

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Message 5 of 8
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What does that command mean?

 

Did you look at the examples for Modbus that are installed with the libraries such as the Master?

 

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Message 6 of 8
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There's like 3 or 4 MODBUS libraries, so without you telling us which one you actually got, it's difficult to help.

 

As a general note, to send what you're trying to send, you're probably looking for something called "Modbus write multiple holding registers.vi", and you need to convert those 3 things you're trying to write from hex into 16-bit unsigned integers.  So the "data send input" might be labeled something like "Registers", and would be an array of U16.

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Thanks to everyone for all the help.  I was able to get it to work:)

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