Historical Event Access
Contents
Introduction
Historical Event Access addresses the handling of historical time series events. The AddressSpace of HEA Servers contains Historical Nodes representing the history of Event Sources (Objects or Views). HEA Clients deal with historical events by accessing these Nodes with the HistoryRead and HistoryUpdate Services.
Examples of historical events are:
- Notifications
- System alarms
- Operator action events
- System triggers (such as new orders to be processed)
Note – Historical Access is specified in OPC UA Part 11.
Historical Event Access Capabilities
Base Access
URN: https://opcfoundation.org/wiki/index.php/Historical_Event_Access#Base_Access
Discovery ID: HE
Description
This capability indicates the base support of historical time series events including reading.
Usage Considerations
- Retrieval of SOE data.
- Root cause analysis.
Conformance Testing
Insert-Update
URN: https://opcfoundation.org/wiki/index.php/Historical_Event_Access#Insert-Update
Discovery ID: HE
Description
Modify existing historized Events or add historized Events that are not in time series order.
Usage Considerations
- Storage of Events received late.
- Inserting missing Events.
- Correction of incorrect Events.
Conformance Testing
Delete
URN: https://opcfoundation.org/wiki/index.php/Historical_Event_Access#Delete
Discovery ID: HE
Description
Ability to permanently remove historized Events.
Usage Considerations
- Removal of out of service data.
- Removal of redundant data.
Conformance Testing