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.