west instruments modbus rs485 MLC9000 MLC 9000 lookout

[unclebump]

The S300004 looks like the correct format to read I16 data. Can you post your code that you are reading with?? Maybe there is a format problem in that code.

[stefan!]

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@stefan! wrote:
I know the value of 0004, it is -10 (or FF9C (hex)),

This is wrong. Correct is:
-10 (int) = FFF6 (hex) , but return value is FF9C (hex)= -100 (int)
-20 (int) = FFEC (hex) , but return value is FF38 (hex)= -200 (int)

[stefan!]

Hi Unclebump,

the code is still very much beta,
I wrote a simple version, the name is
"simple version".

I hope you can do something with the
code, if you don't have the hardware.

Of course the attached program is not the OPC-Server,
the OPC-server is just the NI Modbus RTU OPC-server.

In the "NI Modbus RTU OPC-Server" I just used the data
member S400004 (or S300004) and received
in the "NI server explorer" the wrong value
800, regardless of the value on the address
0004 in my MLC9000.

Regards, Stefan

[unclebump]

Can you save this as 7.0 format.

[stefan!]

LV-7.0

[unclebump]

Here is a modbus master llb file that I got from somewhere on the web. Try this and see what you get. I think it will work without using the server.

[stefan!]

Thanks for the drivers!!!!
My program also works, but without the "NI Modbus RTU OPC Server", I have the impression, that there is a bug in
the object file ("*.cbx"-file) for "Modbus RTU".

The Documentation of your Modbus master is in spanish (perhaps someone can translate it for the labview community?).

I think I will work without OPC-Server and publish
the values in global variables.

Regards, Stefan

[unclebump]

Good to hear. If you are going to do a bunch of modbus work, I would recommend getting the DSC engine software.

[stefan!]

Thanks for the tip! Bye Stefan

[stefan!]

Hello Unclebump,

thank you for the tip with the Datalogging and Supervisory Control Module (DSC).
The DSC is a bit buggy (I had already four crashes of labview, while training
with the getting started manual).
But this is exactly what I want, a layer between the OPC items and the indicators
and controls on my front panel.

Regards, Stefan