Historical Event Access

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.

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Conformance Testing

Client	Server
Read historized events	Provide read access to historized events

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.

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Conformance Testing

Client	Server
Client is able to modify an archive with historized events: Insert Update Replace	Server allows modifying its archive with historized events: Insert Update Replace

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.

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Conformance Testing

Client	Server
Client supports deletion of historized events	Server allows deletion of historized events