How do I restrict a PI tag value range, e.g. if I don't want a tag value to be >100 even if the source value is?
It depends on how the PI Point is being updated.
If you want to build some data quality filtering you could perform this via AF Analyses and create a new data stream (a new 'cleansed' PI Point), where if the new value (from the event triggering of your analysis) was out of range then you could either clamp or ignore the value via your AF Analysis expression.
If you are looking to restrict data before it streams into the PI Point via a PI Interface then that it likely more difficult to achieve.
Thanks Rhys, looks like AF is the way to go so, just thought there may be an easy way to do it in the tag configuration.
PI Point Type Int16 can be restricted to Zero + Span range, but other Point Types don't work the same.
The PI OPC DA Interface allows some Scaling and Transformation, but I don't think that will solve your issue: https://livelibrary.osisoft.com/LiveLibrary/web/pub.xql?action=home&pub=Interfaces-v1&lang=en&docid=GUID-0F696C06-7296-4…
So how do you restrict Int16 to zero+span range?
The Span is the difference between the top of the range and the bottom of the range. It is required for all numeric data type points.
For float16 point types, the Span is used with the Zero for scaling values in the archive. The Span must be a positive value. If the value for a point type float16 point is greater than the top of range, it is recorded in the archive as Over Range. For other point types, Zero and Span do not affect the values recorded in the archive.
The Span is also used when defining a PI ProcessBook trend with a vertical scale of database.
This attribute is not used for non-numeric points.
The Span for a tag can be changed without affecting data already in the archive. For points of type float16, the old Span is used for retrieving the archive data collected before the edit. The new Span is used for data collected after the edit. When Span is changed, the exception and compression deviation percents are preserved. This means that the ExcDev and CompDev fields, which are expressed in engineering units, are modified internally. If any of the deviation fields is specified in the editing operation they take precedence.
Some interfaces might use Span information to filter incoming data. These interfaces often convert out- of-range data to digital states over range and under range. However, interfaces might use Span configuration in other ways. The PI Server itself does not change out of range data except for tags of type float16. So you can't filter with Int16.
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