C1 (critical): a boundary tie cluster larger than NumValuesPerNode could
silently truncate a resumed read to GoodNoData, permanently dropping the
un-emitted ties — the (timestamp, skip) cursor cannot advance past a single
timestamp the fixed-(start,end,cap) backend keeps re-returning. Now detected
and failed LOUDLY per node with BadHistoryOperationUnsupported + a log naming
the tag/timestamp/cap; documented in Historian.md with the larger-cap remedy.
Regression test Raw_tie_cluster_larger_than_page_fails_loudly_not_silently.
I3: build HistoryData before Save() so a projection failure can never orphan a
stored continuation cursor.
N1 (YAGNI): drop the never-produced HistoryReadKind enum + Processed-only
Aggregate/IntervalTicks fields from HistoryContinuationState — only Raw pages.
N3: ComputeResumeCursor guards its documented non-empty precondition.
I1: document InMemoryHistoryContinuationStore's eventual-consistency (test double).
Build clean, 182/182 OpcUaServer tests pass.
The Wonderware historian backend is single-shot — it returns up to
NumValuesPerNode samples with a null continuation point — so paging is
synthesised server-side, time-based, for the only count-capped arm (Raw):
- A full page (count == NumValuesPerNode, NumValuesPerNode > 0) emits an
opaque 16-byte continuation point and stores a resume cursor; a short page
(or NumValuesPerNode == 0 "all values") emits none.
- A resume read takes the stored cursor, reads the next page from the boundary
forward, and emits a fresh CP only if that page is also full.
- The resume cursor is tie-safe (HistoryPaging.ComputeResumeCursor /
TrimBoundaryDuplicates): the next page resumes from the boundary timestamp
INCLUSIVE and drops the head ties already returned, so samples sharing the
boundary SourceTimestamp are neither duplicated nor skipped.
Continuation points are bound to the OPC UA session via the SDK's
ISession.SaveHistoryContinuationPoint / RestoreHistoryContinuationPoint store
(SessionHistoryContinuationStore) — capped by ServerConfiguration.
MaxHistoryContinuationPoints (default 100, oldest-evicted) and disposed on
session close. releaseContinuationPoints is honoured via an override of
HistoryReleaseContinuationPoints (the base dispatcher routes release-only reads
there, never to the per-details arms). An unknown / evicted / released point
resumes to BadContinuationPointInvalid.
Processed and AtTime stay single-shot: neither details type carries a client
count cap, so the single-shot backend returns the complete result in one read
and there is no "full page" signal to page on (spec-conformant). Modified-value
history remains out of scope.
The pure paging decisions + CP store contract are unit-tested via HistoryPaging
+ InMemoryHistoryContinuationStore; the full multi-page round trip is driven
end-to-end through the node manager with an in-memory store + a series-backed
fake historian (the in-process harness is session-less).
The gate reads the literal role string OpcUaDataPlaneRoles.AlarmAck = "AlarmAck"
(OtOpcUaNodeManager.cs:643), but the Role-grant-source section told operators to map
their alarm-ack group to "AlarmAcknowledge" (the PermissionFlags ACL bit, a different
vocabulary) — which silently never satisfies the ack gate. Fix the three role-string
occurrences + add a code-true note; generalize the scripted-alarm note to native alarms.
Add AllDeadLetters probe to Native_alarm_during_reconnect_is_dropped_not_forwarded so the
test genuinely guards the Reconnecting state's Receive<NativeAlarmRaised> drop handler —
removing that handler would now cause a dead-letter and fail the assertion (false-negative
gap closed). Reword the ScriptedAlarms.md severity-mapping note: "snaps on the first
transition" → "every transition maps … overriding the authored seed from the first
transition onward", clarifying that MapSeverity runs on every event, not just the first.
Mirror ModbusDriverFactoryExtensions: NEW OpcUaClientDriverFactoryExtensions
(Register + CreateInstance deserialising OpcUaClientDriverOptions, like the
probe) + one line in DriverFactoryBootstrap.Register. Unblocks the first
end-to-end live equipment-tag value (live-proves the FullName→NodeId router).
Mirror VirtualTagHostActor's _nodeIdByVtag pattern for driver values: a shared
EquipmentNodeIds helper (kills the duplicated formula), DriverInstanceId on
AttributeValuePublished, and a (DriverInstanceId,FullName)->NodeId[] map built +
resolved in DriverHostActor.ForwardToMux. No OpcUaPublishActor change.
Driver-value delivery only; native alarms + historian remain separate.
18-task plan to make GalaxyMxGateway an Equipment-kind driver: retire the
SystemPlatform NamespaceKind split + mirror + alias/relay machinery, author
Galaxy points as ordinary equipment tags via the standard TagModal. Mostly
deletion + a single EF migration dropping the per-kind unique constraint.
Phases B (native alarms) + C (server historian) remain out of scope.
Co-located .tasks.json for resume.
Brainstorming-approved design to normalize GalaxyMxGateway into the standard
Equipment-driver model: retire the SystemPlatform/Equipment namespace split +
the SystemPlatform mirror + the alias-tag/relay machinery, author Galaxy points
as ordinary equipment tags, port native IAlarmSource alarms onto the
equipment-tag materialization path, and add a driver-agnostic server-side
HistoryRead backend (over the existing Wonderware Historian reader). Three
phases (A de-split + UI, B native alarms, C historian); clean break, no
migration converter; one EF migration to drop NamespaceKind.
11-task TDD plan from the approved alias-tag design. Approach A (reuse
Tag entity, broaden composer/artifact equipment-tag filter); converter
rewrites relay VirtualTags as alias Tags. No entity/EF migration.
Equipment exposes a Galaxy attribute under a friendly UNS name as a
first-class driver-bound Tag (alias) instead of a relay VirtualTag.
Approach A: reuse the Tag entity, broaden the equipment-tag filter to
admit GalaxyMxGateway-backed equipment tags; no entity/EF migration.
Includes a relay->alias converter (per-equipment + fleet-wide).
Update Uns.md to show Equipment as a leaf in the browse tree (Area → Line →
Equipment), add the /uns/equipment/{id} page with its Details/Tags/Virtual
Tags/Alarms tabs, and adjust the actions table and sub-sections accordingly.
ScriptedAlarms.md and AlarmTracking.md required no changes — neither
referenced the standalone /scripted-alarms editing page.
Replace the modal-based equipment editor on /uns with a dedicated
/uns/equipment/{id} page carrying Details/Tags/Virtual Tags/Alarms
tabs; trim the UNS tree so Equipment is a leaf that links to the page;
remove the standalone /scripted-alarms pages in favour of the per-
equipment Alarms tab. Reuses TagModal + VirtualTagModal unchanged; only
the alarm editor is new. No entity/EF-migration change.
Joseph Doherty