test(opcuaclient): event-history smoke + docs(historian): driver event passthrough

2026-06-18 06:12:51 -04:00
parent 68637396b5
commit 7a3d2712c0
2 changed files with 41 additions and 0 deletions
@@ -113,6 +113,19 @@ Wonderware historian using that source. Event-field projection supports the stan
 `BaseEventType` select clauses — `EventId`, `SourceName`, `Time`, `ReceiveTime`, `Message`,
 and `Severity`; an unsupported select operand returns a null field (spec-conformant).

+### OpcUaClient driver — upstream passthrough for all four variants
+
+The OpcUaClient driver's `IHistoryProvider` implementation forwards **all four** history-read
+variants (Raw, Processed, AtTime, and Events) to its upstream OPC UA server. For the Events
+variant it sends a fixed canonical `BaseEventType` `EventFilter` selecting the standard six
+fields (`EventId`, `SourceName`, `Time`, `ReceiveTime`, `Message`, `Severity`) and maps the
+upstream `HistoryEvent` onto `HistoricalEvent` — the same six-field projection the OtOpcUa
+node-manager itself projects when serving event history. This is a **driver-level capability**:
+the OpcUaClient driver acts as a passthrough to whatever historian the upstream server exposes,
+and is independent of the single server-side `IHistorianDataSource` backend
+(`WonderwareHistorianClient` / `NullHistorianDataSource`) that the OtOpcUa node-manager
+dispatches HistoryRead to for tags on other drivers (Galaxy, Modbus, S7, etc.).
+
 ### Graceful degradation

 | Situation | HistoryRead status |