OPC UA Client Histories

This topic explains how the OPC UA collects histories using the timestamps for the points.

Starting with the Niagara 4.15 and Niagara 4.14.u1 releases, the OPC UA driver enables users to create and manage historical data by storing time-stamped values. When an OPC UA server gathers historical data, it collects two timestamps for each data point: the Source Timestamp and the Server Timestamp.

The OPC UA Client receives the Source and Server timestamps for proxy points. These two timestamps are defined as follows:

Source Timestamp:: This timestamp is generated by the device or system, reflecting the time when the data was generated by the source.
Server Timestamp:: This timestamp is generated by the server, indicating the time when the server received and stored the data.

You can configure history records to use the Server Timestamp by setting the Use Server Timestamp property.

When importing histories, if you set Use Server Timestamp to true, the system will use the Server Timestamp. If it is set to false the Source Timestamp will be employed instead.

When adding a new point with a history, navigate to the added point in the point database to configure the Use Server Timestamp property within the point's history extension.