Discovers the surface of aaAlarmManagedClient.dll and stages the worker
csproj reference so subsequent PRs can wire native MxAccess alarm
subscription. Replaces the speculative "operator decision needed
between path 1 and path 2" framing in MxAccessAlarmEventSink with the
validated architecture.
Key findings from the discovery probe:
1. aaAlarmManagedClient.dll is x86 + .NET Framework (mixed-mode
C++/CLI; PE Machine = i386, NativeEntryPoint flag set). The
"x64-only" framing in the prior follow-up was wrong — confused
by the file path under Wonderware\Historian\x64\.
The assembly is bitness- and runtime-compatible with the
worker (net48 x86), so it loads in the existing process. No
sub-process needed.
2. AlarmClient is the public class. Its model mirrors MxAccess:
RegisterConsumer takes a Windows hWnd and the AVEVA alarm
service WM_APP-pokes that hwnd when alarms change. The worker's
existing STA + WM_APP pump can drive both the data-change COM
subscriber and the alarm-client consumer.
3. AlarmAckByGUID(alarmGuid, ackComment, oprName, oprNode,
oprDomain, oprFullName) — the native ack carries the operator's
full identity atomically with the comment. Closes the v1
operator-comment fidelity gap completely.
This PR:
- Adds the aaAlarmManagedClient.dll reference to MxGateway.Worker.
csproj. Worker still builds clean.
- Adds AlarmClientDiscoveryTests as a Skip-gated reflection probe;
flip the Skip parameter to dump the public type surface for
reference. Captured the dump into MxAccessAlarmEventSink
documentation so it doesn't have to be re-run.
- Replaces MxAccessAlarmEventSink's "two paths forward" doc with
the actual wiring plan against AlarmClient's RegisterConsumer +
Subscribe + AlarmAckByGUID surface.
Subsequent PRs (gated on STA + WM_APP integration testing on the
dev rig):
- Wire RegisterConsumer + Subscribe at session-startup; route
WM_APP messages through GetStatistics + GetAlarmExtendedRec into
EnqueueTransition.
- Translate gateway-side AcknowledgeAlarm RPC to a worker command
that calls AlarmAckByGUID with the OPC UA operator's identity;
replaces the worker-pending diagnostic from PR A.3.
- Translate gateway-side QueryActiveAlarms to a worker command
that walks GetStatistics's reported handles via GetAlarmExtendedRec.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty