Creating Tags in the Redundant Historian

Tag creation for the MultiHistorianAccess class is similar to the HistorianAccess class.

Example

HistorianTag myTag = new HistorianTag();
myTag.TagName = "MyRedundantIntegerTag";
myTag.TagDataType = HistorianDataType.Int4;

UInt32 tagKey;
HistorianAccessError error;
if (!multiHistorian.AddTag(myTag, out tagKey, out error))
    Console.WriteLine("Failed to request multi-historian tag creation: {0}",
        error.ErrorDescription);

If the AddTag() call succeeds, the SDK application should preserve the tagKey returned by that method and use it later for streaming values for that tag.

If it is necessary to ensure that the tag is physically created on at least one of currently available historian partners, you can use the HistorianTagStatus object for the MultiHistorianAccess class the same way it is used for the HistorianAccess class. In the MultiHistorianAccess case, it represents a combined multi-historian tag status aggregated from two internal HistorianTagStatus sub-objects, which can be iterated through and examined separately if needed.