IPIValueAttribute Interface

                                    

 

The IPIValueAttribute interface is a secondary interface supported by the PIValue object.   The interface implements simple access to the Value attributes named Questionable, Substituted, and Annotated (referred to as flag bits) and annotations associated with a PIValue object representing a snapshot or archive event from a PI server. A PIValue object can be created by an application or generated from a calculation or data retrieval call to a PI server.  In either case the flag bits may be set(on) or not set(off). This interface provides quick access to those flag bits without dealing with collection logic.

In contrast, the ValueAttributes collection provides access to existing PIValue attributes as well as future additions or attributes of user created PIValue objects not representing snapshot or archive events.

Remarks

Even if the PIData.RetrievalAttributes collection did not contain the Questionable, Substituted, and Annotated values when retrieving data from the PI server, the flag and the flag bits of the IPIValueAttribute interface still contain the correct values for the associated PI events. The flag and flag bits from the IPIValueAttribute interface match the values in the flag array returned from the IPIValues2.GetValueArrays method. The Annotation property, unlike the flag bits, is only available if requested through the PIData.RetrievalAttributes collection before a data retrieval. Unlike this interface, the PIValue.ValueAttributes collection only shows attributes specified in the PIData.RetrievalAttributes collection before the data call was made.
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