Reflection on aaAlarmManagedClient.AlarmClient shows it implements
only IDisposable (no [ComImport] interface, no class GUID) and
has a single field "CwwAlarmConsumer* m_almUnmanaged". So
AlarmClient is a C++/CLI managed wrapper around a native C++
class -- NOT a COM-interop class. The DateTime conversion happens
INSIDE AVEVA's wrapper IL, not at the .NET-COM marshaling
boundary. There's no separate COM interface to QI to.
Revised approach (in docs/AlarmClientDiscovery.md):
A. wnwrapConsumer.dll -- separate standalone COM library AVEVA
ships at "C:\Program Files (x86)\Common Files\ArchestrA"
exposing WNWRAPCONSUMERLib.wwAlarmConsumerClass with
SetXmlAlarmQuery / GetXmlCurrentAlarms. XML-string output
bypasses FILETIME marshaling entirely. Best fit -- real COM,
self-contained, conventional production-grade approach.
B. Patch aaAlarmManagedClient.dll IL -- direct but modifies a
vendor binary, brittle to upgrades.
C. Reflect into m_almUnmanaged and call native vtable directly
-- requires reverse-engineering the C++ class layout.
Picking A. Probe restored to Skip; next commit starts the
wnwrapConsumer integration.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
f490ae2593