Read from a Power Meter with Modbus

[MaSta]

In what VI? MAX should work, unless the serial VISA passport isn't activated or the ModBus message you sent from there was in incorrect format (backslashes before hexbytes=.

[K C]

Unless you know how a ModBus message looks like and know the CRC you cannot talk ModBus in MAX

At this point you have to show (the VI's) what your are doing. 

[MaSta]

I supposed he a complete test message intercepted somewhere from the ModBus VIs. 

What came to my mind right now: serial line specificed RTU and ASCII format. Could also be something here

[Wavicle]

This is the VI I'm trying to use, as I said I am new with all these connections in Labview.

How do I know if the VISA passport is activated? 

In the device user manual I have hexadecimal codes for instructions,0x03 for example, can MAX read them?

[Wavicle]

I tried both formats and the error is the same except the name of the format in the error changes

[MaSta]

The error, did it come from the device, the power meter, or from some VI? Because if from the device it would at least confirm that communication works and the power meter received the messages.

VISA passport: in MAX, VISA options. If serial line support is installed at all, the passport would be activated by default. 

I cannot open and run your VI, version too new.

[billko]

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@Wavicle wrote:

In the NI MAX I select the connection, wich appears with the name ASRL3::INSTR, I try to test the connection with the VISA test panel an I get the following error: VISA: (Hex 0xBFFF0015) Timeout expired before operation completed. but even if set the timeout option to 20 seconds the error appears after less than 2 seconds.

Maybe the error is in the VI, something that I need to set in the MODBUS VIs?

Thanks

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Oops I should've read all the comments before replying to this one.  I see you at least know what command you want to send.

[K C]

Can you also post a manual of the powermeter here ?

And which register you are trying to read  ?

[Wavicle]

Passport is activated.

When the error appears the Read Holding registers VI blinks

[Wavicle]

Of course

I am trying to read the active power (page 15 of the user manual)