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Calculations - DeltaTotalCount Cannot Exceed Limits of Source DataType

When using the DeltaTotalCount function, it seems like it can't return a value that exceeds the maximum value of the source tag datatype.

For example, if a tag is being recorded as a UI2 datatype which has a range of 0-65535, the DeltaTotalCount function will only work if the sum is less than the maximum value of 65535.

In the DeltaTotalCount_TestData attached, the value of the tag is incrementing by 10000 every minute for 8 minutes. It rolls over from 60000 back to zero to demonstrate using the DeltaTotalCount function. If the duration for the aggregation is set to 7 minutes, DeltaTotalCount returns 60000 correctly. But if the duration is set to 8 minutes, the calculation encounters an error.

I tried setting the output type of the calculation to UI8 explicitly (as shown in the last photo) but this didn't seem to help.

One workaround is to explicitly set the datatype of this tag in the OPC collector to UI8, but this is not always feasible.

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  • Hi laruer ,

    I was able to reproduce this as well. It is the nature of that aggregate as the API and Axiom also throw an error when it exceeds the range of the data type. I'll submit a bug report.

    Thanks for letting us know!

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