Errata exists for this version of the document.

6.2 defines additional codes and rules that apply to the StatusCode when used for HistoricalNodes .

The general structure of the StatusCode is specified in OPC 10000-4. It includes a set of common operational result codes which also apply to historical data and/or Events.

In OPC UA Historical Access the StatusCode is used to indicate the conditions under which a Value or Event was stored, and thereby can be used as an indicator of its usability. Due to the nature of historical data and/or Events, additional information beyond the basic quality and call result code needs to be conveyed to the Client, for example, whether the value is actually stored in the data repository, whether the result was Interpolated, whether all data inputs to a calculation were of good quality, etc.

In the following, Table 17 contains codes with Bad severity indicating a failure; Table 18 contains Good (success) codes.

It is important to note that these are the codes that are specific for OPC UA Historical Access and supplement the codes that apply to all types of data and are therefore defined in OPC 10000-4 , OPC 10000-8 andOPC 10000-13.

Table 17 – Bad operation level result codes

Symbolic Id	Description
Bad_NoData	No data exists for the requested time range or Event filter.
Bad_BoundNotFound	No data found to provide upper or lower bound value.
Bad_BoundNotSupported	Bounding Values are not applicable or the Server has reached its search limit and will not return a bound.
Bad_DataLost	Data is missing due to collection started/stopped/lost.
Bad_DataUnavailable	Expected data is unavailable for the requested time range due to an un-mounted volume, an off-line historical collection, or similar reason for temporary unavailability.
Bad_EntryExists	The data or Event was not successfully inserted because a matching entry exists.
Bad_NoEntryExists	The data or Event was not successfully updated because no matching entry exists.
Bad_TimestampNotSupported	The Client requested history using a TimestampsToReturn the Server does not support (i.e. requested Server Timestamp when Server only supports SourceTimestamp).
Bad_InvalidArgument	One or more arguments are invalid or missing.
Bad_AggregateListMismatch	The list of Aggregates does not have the same length as the list of operations.
Bad_AggregateConfigurationRejected	The Server does not support the specified AggregateConfiguration for the Node.
Bad_AggregateNotSupported	The specified Aggregate is not valid for the specified Node.
Bad_ArgumentsMissing	See OPC 10000-4 for the description of this result code.
Bad_TypeDefinitionInvalid	See OPC 10000-4 for the description of this result code.
Bad_SourceNodeIdInvalid	See OPC 10000-4 for the description of this result code.
Bad_OutOfRange	See OPC 10000-4 for the description of this result code.
Bad_NotSupported	See OPC 10000-4 for the description of this result code.
Bad_IndexRangeInvalid	See OPC 10000-4 for the description of this result code.
Bad_NotWriteable	See OPC 10000-4 for the description of this result code.

Table 18 – Good operation level result codes

Symbolic Id	Description
Good_NoData	No data exists for the requested time range or Event filter.
Good_EntryInserted	The data or Event was successfully inserted into the historical database
Good_EntryReplaced	The data or Event field was successfully replaced in the historical database
Good_DataIgnored	The Event field was ignored and was not inserted into the historical database.

It may be noted that there are both Good and Bad Status codes that deal with cases of no data or missing data. In general Good_NoData is used for cases where no data was found when performing a simple ‘Read’ request. Bad_NoData is used in cases where some action is requested on an interval and no data could be found. The distinction exists if users are attempting an action on a given interval where they would expect data to exist, or would like to be notified that the requested action could not be performed.

Good_NoData is returned for cases such as:

• ReadEvents where startTime =endTime
• ReadEvent data is requested and does not exist
• ReadRaw where data is requested and does not exist

Bad_NoData is returned for cases such as:

• ReadEvent data is requested and underlying historian does not support the requested field
• ReadProcessed where data is requested and does not exist
• Any Delete requests where data does not exist

The above use cases are illustrative examples. Detailed explanations on when each status code is returned are found in 6.4 and 6.7

The StatusCode in addition contains an informational bit called Semantics Changed (see OPC 10000-4).

UA Servers that implement OPC UA Historical Access should not set this bit; rather they should propagate the StatusCode which has been stored in the data repository. The Client should be aware that the returned data values may have this bit set.