Reading variable list using ANSL UIF library

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1

Hey,

I’ve been trying out to use the ANSL UIF library to connect to a PLC and list the available variables. I’ve started with the sample program available from PVI Development Setup 4.12.8.9 which was able to successfully connect to my PLC and read some variables. I then wrote a separate demo tool to connect and read the modules list, and variables list.

This worked for the modules list, but for the variables list it seems that I get no data in the response, and also no error.

I noted that in the ANSL_UI_V4_en.pdf manual there is a note in ANSLI_CPU_ListVariables stating “This method is not yet supported in ANSL expansion I I !!”, does this mean that this function is not supported?

Thanks

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2

Hi,

not sure what that comment really means.

I haven’t used ANSLUIF for reading / writing variables so far.
But if ANSLUIF works in a similar way as PVI’s Windows DLL interface, then I would expect that ANSLI_CPU_ListVariables(identCpu) should return the global variables of the PLC, and using ANSLI_TASK_ListVariables(identTask → delivered by ANSLI_TASK_Connect) should return the task local variables.

Does your project use CPU global variables? Do you get any response when using ANSLI_TASK_ListVariables on a existing task?

Best regards.

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3

You are absolutely right, I was indeed using ANSLI_CPU, when I should have been using ANSLI_TASK. I thought there would only be one.

Switching to the TASK one works as intended!

Thanks for the clarification!

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