IEC 62541-11-2020 OPC unified architecture – Part 11: Historical Access.
This part of IEC 62541 is part of the OPC Unified Architecture standard series and defines the information model associated with Historical Access (HA). It particularly includes additional and complementary descriptions of the NodeClasses and Attributes needed for Historical Access, additional standard Properties, and other information and behaviour.
The complete Address Space Model including all NodeClasses and Attributes is specified in
IEC 62541-3. The predefined Information Model is defined in IEC 62541-5. The Services to detect and access historical data and events, and description of the ExtensibleParameter types are specified in IEC 62541-4.
This document includes functionality to compute and return Aggregates like minimum, maximum, average etc. The Information Model and the concrete working of Aggregates are defined in IEC 62541-13.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC TR 62541-1, OPC Unified Architecture – Part 1: Overview and Concepts
IEC 62541-3, OPC Unified Architecture – Part 3: Address Space Model
IEC 62541-4, OPC Unified Architecture – Part 4: Services
IEC 6254 1-5, OPC Unified Architecture – Part 5: Information Model
IEC 62541-8, OPC Unified Architecture – Part 8: Data Access
IEC 62541-13, OPC Unified Architecture – Part 13: Aggregates
3 Terms, definitions, and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TR 62541-1,
IEC 62541-3, IEC 62541-4, and IEC 62541-13 as well as the following apply.
ISO and 1EC maintain terminological databases for use in standardization at the following addresses:
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●ISO Online browsing platform: available at htpt://ww.iso.org/obp
metadata associated with an item at a given instance in time
Note 1 to entry: An Annotation is metadata that is associated with an item at a given instance in time.
values associated with the starting and ending time
Note 1 to entry: BoundingValues are the values that are associated with the starting and ending time of a ProcessingInterval specified when reading from the historian. BoundingValues may be required by Clients to determine the starting and ending values when requesting raw data over a time range. If a raw data value exists at the start or end point, it is considered the bounding value even though it is part of the data request. If no raw data value exists at the start or end point, then the Server will determine the boundary value. which may require data from a data point outside of the requested range. See 4.4 for details on using BoundingValues.
Object, Variable, Property or View in the AddressSpace where a Client can access historical data or Events
Note 1 to entry: A HistoricalNode is a term used in this document to represent any Object, Variable, Property or
View in the AddressSpace for which a Client may read and/or update historical data or Events. The terms “HistoricalNode ‘s history” or “history of a HistoricalNode” will refer to the time series data or Events stored for this HistoricalNode. The term HistoricalNode refers to both Historica/DataNodes and HistoricalEventiNodes.
Variable or Property in the AddressSpace where a Client can access historical data
Note 1 to entry: A Historica/DataNode represents any Variable or Property in the AddressSpace for which a Client may read and/or update historical data. “HistoricalDataNode’s history” or “history of a Historica/DataNode” refers to the time series data stored for this HistoricalNode. Examples of such data are:
device data (like temperature sensors)
status information (open/closed, moving)
dynamically changing system data (like stock quotes)
The term HistoricalDataNodes is used when referencing aspects of the standard that apply to accessing historical data only.IEC 62541-11 pdf download.