Extended AlarmClientWmProbeTests to call AlarmClient.GetProviders
after RegisterConsumer. Run 2026-05-01:
GetProviders -> rc=0 count=0 list=[]
Zero alarm providers visible to the consumer. This explains every
preceding probe run — no providers means no alarm events,
regardless of subscription expression or value writes upstream.
Even with a System Platform script flipping
TestMachine_001.TestAlarm001 every 10s during the run,
GetStatistics reported no transitions, no positions[] entries,
no field changes after t=0.85s.
Possible causes (dev-rig configuration, not code):
1. No $Alarm extension on the test bool — flipping the value
writes a value but doesn't fire an alarm.
2. AVEVA alarm-manager service (aaAlarmMgr or equivalent) not
running on this rig.
3. Process security context — providers registered under a
service account aren't visible to a consumer running under
a normal user account.
A.2 implementation is blocked on this until at least one provider
is visible. Once a provider exists, the polling-vs-callback
question is answerable in one probe run; without a provider both
paths return the same "nothing happening" answer.
Probe changes:
- Added in-process MxAccess Write attempt (TriggerWriteValue) —
hit TargetParameterCountException so the Write signature is
not (handle, item, value); reflection diag added but not
resolved. Now disabled in favor of external trigger.
- Added GetProviders enumeration after RegisterConsumer.
- Removed firePrint/clearPrint markers; probe is observe-only.
- Added ArchestrA.MxAccess reference to the test project.
Also updated docs/AlarmClientDiscovery.md with the
alarm-provider-visibility section explaining what's blocked
and why.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
f4423dfb6d