OPC UA Historians Should Store Source Time and Receipt Time
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Global – October 29, 2026 -- Choosing the wrong OPC UA timestamp can reorder events, hide network delay or place valid data outside the historian query window, so most process analysis should use a trustworthy SourceTimestamp as event time and keep collector receipt time as a separate field.
SourceTimestamp stays fixed as data passes through servers
The OPC UA specification defines SourceTimestamp as the time a data source applies to a value, ideally the last change of the value or status, generated as close to the source as possible. It does not change when the value passes through another OPC UA server. That makes it the best fit for sequence-of-events work, batch analysis and calculations tied to when the process changed.