Item 1: IHistorianDataSource.MaxRawValuesPerRead (Gateway: learned ceiling - 16 = L; 0 elsewhere, guard-tested).
RawPageLimit plans every raw page on top of #692's lookahead: with L > 0 the read (page P + boundary ties k
+ lookahead) is <= L, P = min(N, L - k - 1) (uncapped: L - k - 1); no room => straight to the tie-cluster
over-fetch (never an uncapped or underflowing request). One re-plan + re-read when the read taught a new
limit or was refused for crowding pre-window rows (HistoryReadLimitExceededException.PreWindowRows): the
page shrinks by them. Over-fetch bound min(MaxTieClusterOverfetch, L - 1); slice size never 0.
Review fixes: F1 a window starting at/before the epoch counts AVEVA's synthetic row as pre-window (a
ceiling-truncated read was reported complete); F2 the page path disables ReverseRawReader's own re-run
(cold end-only ceiling 20/N=3000 cost 3,023 reads, now <= 40); F3 crowded look-back re-read around, not
refused; F4 the #687 crowding re-read room at least doubles (up to 8 re-reads), so a cluster of hundreds
just before a resume point no longer fails on a default gateway; a crowding refusal that leaves no room
is BadTooManyOperations, never a tick-by-tick cursor.
Item 2: ServerHistorian:EventReadHorizon (default 00:00:00 = exact, unchanged). When set, every fresh
HistoryReadEvents window's earlier bound is raised to now - horizon (both directions, all backends).
Lossy by design; documented.
Item 3 (native TimeAverage/Total re-check) stays blocked on historiangw#27.
Review follow-up: on the Gateway every value is a Double (AVEVA stores a Boolean
as a 0/1 Int2), so the raw-evaluated AtTime interpolated a Boolean node to 0.5.
- IHistorianDataSource gains a default-interface overload
ReadAtTimeAsync(fullReference, timestamps, TypeCode? valueType, ct) that
forwards to the existing one (SqlServer/QuestDB/Null/fakes unchanged).
- OtOpcUaNodeManager.HistoryReadAtTime passes the node's scalar DataType
(AtTimeValueType: built-in type -> TypeCode; arrays/other types => null);
Raw and UNS NodeIds alike.
- GatewayAtTimeReader converts each raw row to the hinted kind BEFORE the shared
AtTimeEvaluator runs (Boolean = value != 0 => stepped; integers => Int64 =>
interpolated, rounded half away from zero, returned as the node's integer
type; floats Double), so the evaluator's own type branch decides.
- AtTimeEvaluator boxed every interpolated Int64 as a Double (`cond ? (long)x :
v` widens to double); its "keeping its type" test passed because Shouldly
ShouldBe compares numbers across types. Fixed (affects SqlServer/QuestDB too)
and pinned with ShouldBeOfType.
The null source has no history in either direction; reporting false
made the server walk an empty reverse events read back through three
empty forward reads. It now answers the reverse overload with the empty
result itself (guard test unchanged: it still declares both members).
A reverse or end-only capped events read on a backend without
SupportsReverseEvents (Gateway, Null) was refused
BadHistoryOperationUnsupported (explicit reverse) or answered with the
OLDEST N ascending (end-only, #675). It is now served newest-first by
the same ReverseWalk as raw reads: page-sized ms-aligned segments,
never answered from a read the source flagged truncated, ties sorted by
EventId (the gateway orders by event time only - the fake shuffles
them per call), one extra event walked to signal 'more', uncapped = one
forward read reversed, and the width + proven-empty stretch carried in
the events cursor. The oversized-cluster over-fetch keeps exactly the
events at T in the same order. A tie cluster over the budget is
BadTooManyOperations. Docs note the gateway's EventReadMaxRows must be
unlimited (it truncates silently).
#669 turned an end-only capped HistoryRead-Raw into a reverse read (start > end)
for every backend; the gateway rejects start > end (InvalidArgument), so on the
default Gateway backend every end-only capped and every explicit reverse raw read
failed the node and was counted as a backend health failure.
- IHistorianDataSource.SupportsReverseRaw (default false; SqlServer/QuestDB/Null
true, Gateway false; guard test pins that every production backend declares it).
- OtOpcUaNodeManager sends a reverse window only to a backend that declares it;
otherwise ReverseRawReader walks (lo, hi] back in bounded forward segment reads
(1 min, x4 while sparse; each <= MaxTieClusterOverfetch + 1 rows; a full read is
re-read narrower, never answered truncated; filtered on sample timestamps, which
also drops AVEVA's fabricated query-start rows; stops at the Unix epoch). A
one-timestamp tie cluster over the bound => BadTooManyOperations.
- ServeRawPagedAsync maps HistoryReadLimitExceededException to BadTooManyOperations.
- GatewayHistorianDataSource.ReadRawAsync refuses start > end unsent, without
recording a health failure.
ServerCapabilities/AggregateFunctions (i=2997) is Part 5's list of every
aggregate the server supports, and live AggregateFilter subscriptions still
compute all 37 SDK aggregates, so it keeps the SDK's full set; only i=11201
follows the backend. A null SupportedAggregates is treated as the interface
default (all) by both the advertisement and HistoryRead-Processed (it used to
NRE inside the batch). Docs: i=2997/i=11201 split and the boot window.
Co-Authored-By: Claude <noreply@anthropic.com>
IHistorianDataSource.SupportedAggregates (default: every HistoryAggregateType)
is the one authority for both ServerCapabilities/AggregateFunctions (i=2997) and
HistoryServerCapabilities/AggregateFunctions (i=11201) and for the up-front
BadAggregateNotSupported in HistoryRead-Processed. Gateway declares
AggregateModeMapper.Served (4), SqlServer/QuestDB AggregateFamilies.Served (17),
Null none. Only the folder references are trimmed; the SDK's calculator
factories stay so live AggregateFilter subscriptions keep working.
Co-Authored-By: Claude <noreply@anthropic.com>
- HistoryUpdate Primary gate now reads IHistoryUpdateRoleView (PrimaryGatePolicy.ShouldServeHistoryUpdate):
the data-plane verdict but CLOSED until this node's first redundancy snapshot, so both pair nodes cannot
accept in the pre-join boot window. Single nodes open on their own singleton's first snapshot; admin-only
nodes register no view => no gate. DriverHostActor publishes it at every Primary-verdict publish point.
- SqlServer v1: the updater throws NotSupportedException on every arm; the node manager maps it to a
node-level BadHistoryOperationUnsupported (was per-item under a Good node for UpdateData/DeleteAtTime).
HistoryWrite bit still advertised on v1 (not knowable at materialise time) — documented.
- The update plan is evaluated before the Primary gate: an unservable request (Remove, IsDeleteModified,
not historized, no updater) is BadHistoryOperationUnsupported off-Primary, not BadInvalidState.
- Local-kind SourceTimestamp converted to UTC before the future-skew compare and sent as UTC.
- Hosted-service wiring extracted to BuildHistoryUpdatePosture and tested (gate source, skew, clock).
- Docs: Historian.md (boot window, ordering, node-level v1, HistoryWrite bit), CLAUDE.md.
Co-Authored-By: Claude <noreply@anthropic.com>
- IHistorianDataSource.SupportsReverseEvents (default false; SqlServer/QuestDB true; Gateway/Null declare false).
The node manager checks it BEFORE calling the source: an end-only capped events read becomes reverse only on
a supporting backend (Gateway, the default, keeps the pre-#675 forward [MinValue, EndTime) paging), and an
explicit reverse read on a non-supporting backend is BadHistoryOperationUnsupported without a call.
- Removed the broad catch (NotSupportedException) in the events path: a NotSupportedException from inside a
backend is now logged as a backend fault (Error), not an 'unsupported' Warning.
- Null declares the reverse overload itself; guard test: every production IHistorianDataSource declares both
the reverse overload and the capability (positive-control scan of all four backends).
- Conformance: capability reported + oversized reverse tie cluster (forward over-fetch reversed == reverse
read order; capped reverse read stopping inside the cluster flags truncation) on SqlServer + QuestDB.
- docs/Historian.md: end-only capped events read is backward on SqlServer/QuestDB, forward on Gateway.
- Endpoint rewrite: the driver now connects to the configured host AND port (scheme
match, advertised path kept) instead of the server-advertised URL — fixes NAT/port-map
upstreams and lets an in-test proxy carry the session (SDK SelectEndpoint rule).
- TcpStallProxy + OpcUaClientDriverStallWireTests: the in-place blip (#670) is now
wire-tested on loopback — one Bad, frozen read stamp, same session, identical value
republished Good, a post-recovery change arrives, no source-time regression after
the SDK's late backlog flush.
- Defect found by that test, fixed: a change published right after a stall rode a
Publish response the SDK timed out and never republished, leaving the node Good on
the pre-change value indefinitely. New trailing reconcile read (Timeout +
KeepAliveInterval after recovery) publishes any Good value newer than the last
accepted one, through the replay guard's mark.
- IDriverConnectionLossSource (Core.Abstractions): opt-in definitive-loss signal.
DriverInstanceActor attaches in PreStart / detaches in PostStop and turns a raise
into a disconnect only while Connected. OpcUaClient raises once per session on
keep-alive BadSessionIdInvalid/BadSessionClosed/BadSessionNotActivated/
BadServerHalted (measured: the SDK never re-opens a halted channel) or a dropped
subscription; ambiguous codes stay with the #527 watchdog.
- Replay guard: one Information summary per recovery when the window closes
("dropped N late notifications across M refs"), with a timer so quiet
subscriptions log it too.
- ReconnectPeriod deleted (options, AdminUI form, docs, tests); stored configs that
carry reconnectPeriod still parse in the factory, probe and browser.
- Docs: OpcUaClient.md, DriverLifecycle.md, driver-specs.md, CLAUDE.md.
- IHistorianDataSource.ReadEventsAsync(..., bool reverse, ...) overload: reverse = Part 11 window (lo, hi]
newest-first by (time, id) DESC. Default forwards forward reads and throws NotSupportedException for
reverse (Null); Gateway refuses explicitly (ascending-only stream). Server answers
BadHistoryOperationUnsupported instead of silently returning the earliest N ascending.
- SqlServer / QuestDB serve reverse natively (ORDER BY time DESC, id DESC + TOP/LIMIT).
- Node manager: reverse event reads page with continuation points; direction stored in the cursor
(HistoryContinuationState.Reverse) so a resume continues in the cursor's direction; reverse tie clusters
over-fetched forward and sliced from the newest end (SliceTieCluster(reverse:)); end-only reads with a
cap page backward from EndTime (mirrors raw).
- Resumed event pages over-fetch by the boundary skip, so every non-final page is a full cap page.
- Tests: node-manager reverse paging (ties, clusters, coarse resolution, overfetch bound, resume
direction both ways, end-only, unsupported backend); shared EventReadConformance on SqlServer +
QuestDB; over-the-wire reverse paging; offline Gateway pin of the UTC DateTime.MaxValue bound through
the published client's proto conversion (in-process gRPC capture) and FILETIME.
- docs/Historian.md event paging section.
- HistoryModifiedValue gains explicit SourceTimeUtc (SqlServer + QuestDB populate it); the node manager's resume cursor uses it instead of the prior value's nullable source timestamp (MinValue for inserts).
- ACL test now uses a trail-returning data source and asserts Good + data on the allow leg.
- Node-manager tests: end-only backward open-ended paging, reverse resume cursor, null-prior cursor.
- QuestDB updater logs a Warning (tag + time range) when a sample write fails after its trail rows landed.
- docs/Historian.md: rolling-upgrade window, IDENTITY-vs-commit ordering, QuestDB cross-node ModifiedId clock ordering.
Every HistoryUpdate a SQL backend applies now leaves a modification trail
(prior value, principal, Part 11 update type, modification time), and
HistoryReadRaw with IsReadModified=true serves it as HistoryModifiedData.
- Core: HistoryUpdateContext threaded into all three IHistorianDataUpdater
methods; IHistorianDataSource.ReadModifiedAsync (default NotSupported =>
BadHistoryOperationUnsupported on Gateway/Null); HistoryModified* contracts.
- SqlServer: schema v2 (002_sample_modified.sql, RequiredVersion=2, docs copy);
trail written by OUTPUT ... INTO on the same MERGE/DELETE statement, so a
failed update leaves no audit row; retention purges SampleModified per tag on
the source-time cutoff; ReadModifiedAsync keyed on (SourceTimeUtc, ModifiedId).
- QuestDB: append-only {prefix}sample_modified (TTL like samples), trail row
written BEFORE the change (orphan-on-crash, never an untracked change);
existence reads now carry the prior value; ReadModifiedAsync.
- Node manager: modified reads dispatch + page via the #669 continuation store
(HistoryContinuationState gains HistoryCursorKind + LastModifiedId), gated by
the existing HistoryRead decision; session principal / key id passed to the
updater. IsDeleteModified stays unsupported.
- Client.CLI: historyread --modified.
- Tests: node-manager dispatch/paging/cursor binding/principal threading,
over-the-wire HistoryModifiedData, shared ModifiedValueConformance on both
backends, SqlServer atomicity (forced trail failure => no change) + v1->v2
upgrade + retention trail purge.
- Docs: Historian.md (Modified-value history section, schema v2 upgrade note),
security.md, Client.CLI.md, CLAUDE.md.
M1: the time-weighted family (incl. Total, formerly a pushed-down SUM) streams
raw window rows into the C# evaluator. New shared knob
ServerHistorian:MaxTimeWeightedRawRows (default 1,000,000; <=0 unbounded with a
Validate warning) flows through HistorianBackendRegistry into both providers.
The window query is capped at cap+1 (SQL Server TOP (@maxRows), QuestDB LIMIT $4);
one row past the cap throws the new Core.Abstractions
HistoryReadLimitExceededException, which the node manager maps to
BadTooManyOperations for that node. Not counted as a backend health failure;
bound rows are not counted; per-sample aggregates are not capped.
M2: reverse Interpolative is anchored at the later time (Part 13): points at
End - i*interval, emitted latest first. 10:00->09:00 @1h yields 10:00.
L1: Partial bit (0x4, = Opc.Ua.AggregateBits.Partial) on non-Bad results of a
truncated last interval (time-weighted family; per-sample family is a follow-up).
L2/L3: aligned with the SDK AggregateCalculator.GetTimeBasedStatusCode
(decompiled from Opc.Ua.Server 1.5.378.106): TreatUncertainAsBad=false counts
Uncertain time (Uncertain samples, held-into-outage, extrapolation) as Good
time; data but no non-Bad time => generic Bad (0x80000000); BadNoData only
when there is no data at all. Consequence: a live tag's latest interval reads
Good (documented).
L5: release note no longer claims Total matches the Gateway Integral exactly
(AVEVA's divisor is unverified); it notes Total is now evaluated in C# and
subject to the cap.
Tests: unit (reverse Interpolative x3, Partial, Bad vs BadNoData incl. an
open-ended outage, cap helpers, SDK bit oracles); conformance (reverse
Interpolative, raw-row cap at/over/0, bounds not counted, health unaffected);
node manager BadTooManyOperations; options default + warning. Each new
behaviour falsified by mutation (aggregator x9, data-source cap checks on
both backends against the real DBs, node-manager catch).
New AggregateFamily.TimeWeighted serving TimeAverage, TimeAverage2, Total,
Total2 and Interpolative, evaluated by the shared Sql.Common
TimeWeightedAggregator for both SQL backends (identical results by
construction). HistoryAggregateType gains TimeAverage2 + Total2 (appended);
OtOpcUaNodeManager.MapAggregate maps their NodeIds. Gateway's mapper already
refuses unknown defined members => BadAggregateNotSupported per node.
Semantics (server defaults, client AggregateConfiguration ignored):
TreatUncertainAsBad=false, PercentDataBad=PercentDataGood=100,
UseSlopedExtrapolation=false. Sloped for Double/Int64, stepped for Boolean;
a usable sample followed by a Bad one is held up to the outage (AtTime rule);
stepped Uncertain extrapolation past the last sample. TimeAverage/Total use
interpolated bounding (bridge outages); TimeAverage2/Total2 exclude Bad time.
Bounding values: latest usable + latest any before start, first any + first
usable at/after end (four TOP 1 / LIMIT 1 seeks).
CLIENT-VISIBLE: Total on SqlServer/QuestDb was SUM of samples; it is now the
time-weighted integral (TimeAverage x interval seconds), matching Gateway's
Integral. Release note in docs/Historian.md.
Trade-off (deviation from the preferred hybrid pushdown, allowed by the
design): the time-weighted family is NOT pushed down. Each read streams the
window's rows plus the four bounds (SQL Server: one five-result-set batch;
QuestDB: bounds UNION ALL + window select) into the C# evaluator. Network is
O(samples in window), memory O(buckets). Writing the per-segment
interpolation/edge splitting twice in two SQL dialects and keeping them
bit-identical was judged the bigger risk; this also makes the QuestDB
lag/lead spike moot.
Tests: 35 hand-computed TimeWeightedAggregator unit cases (each of 10
implementation mutations goes red); served-aggregate pin 13 -> 17;
conformance sparse fixture (intervals wider and narrower than sample gaps)
+ an outage straddling both window edges (each of the four SQL seeks
disabled in turn goes red); node-manager NodeId mapping test.
IHistorianDataSource.TimestampResolutionTicks (default 1; QuestDB 10). A drained tie
cluster now steps off T by the resolution, so a forward one-value-per-page read on a
microsecond backend no longer re-reads the same sample forever (C1). QuestDB AtTime
results carry the client's original request time (M3); regression for the NEXT seek
skipping a tombstone (M1). Conformance backend wires the real writer and updater.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Since #516 a DriverConfig change is stop + respawn, so DriverSpawnPlan.ToApplyDelta
was always empty and the in-place path had no producer. #663 and #664 were both
latent bugs in it. This deletes it:
- host: ApplyChildDelta, _pendingDelta, HandleApplyResult and HandleDeltaApplied
- plan: DriverSpawnPlan.ToApplyDelta
- actor: the ApplyDelta, ApplyResult and DeltaApplied messages, the Connected
reinit handler and the mid-connect AdoptConfigDuringInit
- tests: the actor tests that drove the seam
IDriver.ReinitializeAsync and each driver's implementation and unit tests stay.
Comments and docs that cited AdoptConfigDuringInit as the reason a driver must
release prior state at init now cite the IDriver contract and overlapping
retries, which still apply.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
After an OpcUaClient respawn an upstream inactive+unacked condition went out as
Retrigger+Clear (duplicate Activated+Cleared rows, Active flicker), and a
first-sight inactive+acked one as Unspecified (an Activated row for an inactive
alarm; a retained-Active host condition never cleared).
- New AlarmTransitionKind.InactiveUnacknowledged: one projection, rows only for
what changed (Activated+Cleared from acked, Cleared from active+unacked, none
when already inactive+unacked).
- OpcUaClient uses it for moves into inactive+unacked; first sight of an
inactive condition is InactiveUnacknowledged or Clear+Acknowledge, flagged.
- Projector: a flagged Acknowledge on an already-acked condition writes no row.
- E2E tests through DriverHostActor.ForwardNativeAlarm (red-proven).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- AlarmTransitionKind.ActiveAcknowledged (appended): active AND acked applied as ONE projection.
Galaxy ActiveAcked snapshot entries and OpcUaClient inactive->(active,acked) use it; the
projector writes 'Activated' only if not already active, 'Acknowledged' only if not acked.
- AlarmEventArgs.IsRestatement (optional, default false): set only by Galaxy snapshot entries
and OpcUaClient first sight. A flagged Retrigger on an Active+unacked condition with the same
message and severity, or a flagged Clear on an inactive condition, writes no /alerts row.
- NativeAlarmProjector reports the history rows per transition; ForwardNativeAlarm writes one
row per entry. Unflagged sources (FOCAS/MTConnect/AbCip, live Galaxy) are unchanged.
- Tests: projector rules each with a must-write control; OpcUaClient transition table;
Galaxy feed/driver mapping; Galaxy + OpcUaClient end-to-end through DriverHostActor.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
HistoryRead is served server-side by IHistorianDataSource; nothing ever dispatched
to a driver's IHistoryProvider. Removes IHistoryProvider, the OpcUaClient history
passthrough, DriverCapability.HistoryRead (+ resilience tier rows and AdminUI row),
HistoryReadStatusException and its node-manager catches, and the tests that only
covered them. Shared result types and HistoryAggregateNotSupportedException stay
(moved to Historian/HistoryReadContracts.cs). A stored ResilienceConfig still
carrying a HistoryRead key parses (diagnostic only; new test).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
AlarmEventArgs gains optional OpcUaSeverity (supersedes the four-bucket mapping, clamped
1..1000) and QualityStatusCode (projected onto the condition's Quality). An Unspecified-kind
event carrying a quality is a quality-only annotation: the host updates the condition but
publishes no alerts row. Both default null, so every existing native source is unchanged.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
MAJOR-1: R4's exact element-type match refused ScadaBridge's CLR-list
writes (its element types are only Boolean/Int32/Float/Double/String/
DateTime) to every Int16/UInt16/Byte/UInt32/Int64/UInt64 array node and a
Double list to a Float array. EvaluateEquipmentWriteStructure now converts
a numeric array of another numeric element type element-wise, CHECKED, into
the node's element type and hands the converted array back through
OnEquipmentTagWrite's ref value, so the node stores and the driver receives
the node's own type. Any out-of-range, fractional-to-integer, NaN/Inf-to-
integer or Float-overflowing element refuses the whole write BadTypeMismatch
(nothing dispatched) - so the UInt32 -> Int32 bit reinterpretation stays
closed. Non-numeric mismatches stay refused. The wrong 'no client relies on
a looser rule' comment is corrected.
MINOR-1: the array-value-to-scalar-node refusal broke writes back to
browse-committed array tags (committed scalar, isArray never set) on
pass-through drivers. It now applies only when the owning driver's scalar
encoder cannot take an array (DriverArrayWriteSupport.
RefusesArrayValueOnScalarTag: Modbus, S7), carried RawTagPlan.
ScalarRefusesArrayValue / UnsReferenceVariable.BackingScalarRefusesArrayValue
-> EnsureVariable(refuseArrayOnScalar) -> a per-node set in the node
manager. OpcUaClient/Galaxy/others keep pre-#610 dispatch. Not on the
classifier whitelist (driver-type edit rebuilds); a mirror whose flag
changes is recreated, not updated in place.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
MAJOR-1: the SDK skips TypeInfo.IsInstanceOfDataType on any node with an
OnWriteValue handler (every writable equipment node), and the node manager's
fail-fast treated numeric<->numeric as compatible, so a UInt32[] to a Galaxy
Int32 array matched MxValueEncoder's int[] arm by CLR covariance and was
written bit-reinterpreted with a Good result. EvaluateEquipmentWriteStructure
now matches an ARRAY write's element type exactly (Byte[]/ByteString the only
equivalence; Variant[]/object[] refused) -> BadTypeMismatch, nothing
dispatched. MxValueEncoder's int[]/long[] arms are exact-type guarded too, and
the Galaxy parity test's false "the SDK refuses" premise is corrected (the
UInt32/UInt64 exclusion is now the encoder's own answer). Scalar writes keep
numeric widening by decision: consumers write CLR-typed values (Double to a
Float node) and every driver's scalar encoder range-checks.
MINOR: Modbus row honours maxRegistersPerWrite (smallest of DriverConfig /
the tag's DeviceConfig, default 123) and FC15's 1968-coil ceiling, and
requires region + numeric address; Modbus/S7/Galaxy require isArray + integer
arrayLength >= 1 (Galaxy: an unbounded node would let a short write resize the
attribute); an array value to a scalar node is refused inline. Docs: Uns.md
array-write rules + upgrade note (ReadWrite array tags become client-writable
on first boot), Modbus.md, Galaxy.md.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Review R1 M1: StopChild evicted the hub cache, but DriverResilienceStatusPublisherService re-emits the
tracker every tick. IDriverCapabilityInvokerFactory.Release (default no-op) now invalidates the pipeline
builder + status tracker; the host calls it before Evict. Test runs a publisher tick after removal, with a
neighbour instance as positive control.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Array nodes were forced read-only for every driver. A new single authority,
Core.Abstractions DriverArrayWriteSupport, says which (driver, element type)
pairs encode a whole-array write: Modbus (Coils / numeric HoldingRegisters),
S7 (Byte/Int16/UInt16/Int32/UInt32/Float32), OpcUaClient (pass-through) and
Galaxy (Boolean/Int32/Int64/Float/Double/String/DateTime). Everything else
stays read-only, so the server never advertises a write the driver refuses.
- Composer derives RawTagPlan.ArrayWritable + UnsReferenceVariable
.BackingArrayWritable at compose time (both seams, byte-parity); the
applier's one writability rule is Writable && (!IsArray || ArrayWritable)
for materialise and surgical paths, raw and UNS alike.
- ArrayWritable is on the classifier's surgical raw-tag whitelist and
mirrored on the UNS record (UnsReferenceBackingParityTests updated).
- Node manager refuses a wrong-length / non-array value on an array node
(BadTypeMismatch) and any IndexRange write (BadWriteNotSupported) inline,
before dispatch; WriteOperate/ACL gates and the revert are unchanged.
- Per-driver parity tests pin the table against the real Modbus write path,
S7 EncodeArrayBlock and Galaxy MxValueEncoder (UInt32/UInt64 excluded:
array covariance reinterprets their bits).
- Over-the-wire proof in OpcUaServer.IntegrationTests (ArrayWriteWireTests).
- ValueRank > 1 documented as out of scope by decision (docs/Uns.md).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty