TimeAverage2/Total2: the interval the data ends inside with no non-Bad time
before its last sample (comms-loss recovery, a single sample) answers that
sample's value (Total2 0), Uncertain + Partial, instead of Bad/BadNoData —
as the SDK. Parity datasets RecoveryEnds, OutageLast, BoolSwitch with
documented masks; ProcessedConformance's reverse TA/Total mask narrowed to
the later-edge-sample interval. Docs: report-by-exception consequence,
outage-last and Boolean differences; CLAUDE.md historian bullet.
Live gate A1 (docker-dev, opc-plc restart / SIGINT / kill): the fast path never fired —
a real process stop delivers no session status; the keep-alives report
BadSecureChannelClosed (0x80860000) once, then BadConnectionClosed (0x80AE0000)
interleaved with BadNoCommunication for the whole outage.
Reproduced in-process with TcpStallProxy.HardClose (reset every connection, refuse new
ones; server and session alive behind it): the identical sequence, and the SDK 1.5.378
session never opens a new connection on its own (48 s with the proxy accepting again,
zero attempts) — a closed channel cannot recover in place.
The driver now treats BadSecureChannelClosed/BadConnectionClosed as definitive on the
SECOND closed-channel keep-alive failure in one outage (a good keep-alive resets the
count), raising ConnectionLost ~1 keep-alive after the drop. BadNoCommunication /
BadRequestTimeout / BadNotConnected (stall/pause) stay with the watchdog; the stall test
still sees no ConnectionLost. New wire test (hard close + reopen ⇒ raised once, SDK never
reconnects, reinit brings the identical value back Good) and unit tests (sustained raises
once; a single blip that recovers does not) — all red on the previous code. Docs updated.
F1: the SDK applies its m_startOfData Partial rule to forward reads only; ours
now does too (AggregateEvaluator.EvaluateAll + TimeWeightedAggregator). New
reverse late-start parity tests through the SDK oracle (unit) and real SQL
(conformance, both backends).
F2: AggregateEvaluator.NeedsEarliestSample — the earliest-sample query runs
only for forward reads of aggregates other than Average, and is bounded by
the window end (SqlServer < @end, QuestDB ts < $2).
F3: per-sample SDK parity extended to Range, Start, End, Delta, Min/Max
ActualTime and PercentGood/Bad (oracle maps StatusAggregateCalculator);
pre-existing definitional differences masked and marked #680.
Docs: Historian.md Partial/SDK-parity sections, CLAUDE.md bullet.
- 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>
1. RewriteEndpointUrl keeps the advertised port when the configured URL names none
(Uri.Port -1 would have sent the session to 4840); port-less + IPv6 tests.
2. The trailing re-read repairs any (value, status) difference that is not older than
the last delivered value — Good->Bad/Uncertain included; a read without a source
timestamp counts as newer; an equal source time with different content is published
(repairs the replay guard's by-design equal-timestamp drop).
3. One driver-wide delivery lock makes decide+publish atomic across live notifications,
the recovery read and the trailing read, so an older value can never land after a
newer one (deterministic race test via a seam).
4. Known gap documented: a ConnectionLost raised while the host is not Connected is
swallowed and that session falls back to the watchdog.
5. Only a SERVER-reported subscription loss raises ConnectionLost; the publishing-stall
heuristic stays with the #527 watchdog.
6. Post-recovery timers run on Task.Delay(…, Clock, ct) with a session-work CTS
cancelled on session release and dispose.
7. Replay summary at Information only when something was dropped (Debug otherwise);
a re-arm reports the superseded window's drops and counts afresh.
8. DriverInstanceActor: AttachHostStatusSource doc comment restored; Reconnecting
swallows a stray DisconnectObserved (test).
9. Stall wire test: 120 s session timeout, 3000-cycle subscription lifetime, one further
bad keep-alive tick, 60 s headroom on the post-recovery waits (5/5 green).
- 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.
- BucketPlan: reverse processed reads anchored at the later time for every
aggregate: window (end, start], partial interval earliest, results stamped
with the later edge, latest first (SDK CreateSlice/GetTimestamp/backward
GetValues). SqlServer adds @bucketAdjustTicks + flips the window predicate;
QuestDB binds BucketBaseUnixTicks. IndexOf is the C# statement of the math.
- Partial bit on the interval the tag's data starts inside (SDK m_startOfData),
every aggregate but Average; per-sample reads fetch the earliest sample.
- Node manager: non-default client AggregateConfiguration =>
BadAggregateConfigurationRejected per node (ServerAggregateConfiguration,
pinned to the SDK AggregateManager defaults).
- GatewayTagProvisioner sends IntegralDivisor = 1.
- SDK parity oracle (Opc.Ua.Server calculators) in unit + both backends'
conformance suites, forward and reverse; remaining divergences documented.
- docs/Historian.md + CLAUDE.md release note (client-visible).
- HistoryUpdate items with SourceTimestamp > now + ServerHistorian:HistoryUpdateMaxFutureSkew
(default 1 day, <=0 disables) => BadOutOfRange in the node manager (every backend, never sent);
clock injected via OtOpcUaNodeManager.Clock (host TimeProvider).
- HistoryUpdate is Primary-only: off-Primary => BadInvalidState per node, after authorization,
same IDriverPrimaryRoleSource verdict as the native-ack gate; HistoryRead ungated.
- SqlServer: base schema requirement back to v1; SupportsModifiedTrail (v>=2). On v1 with
AutoCreateSchema=false: writes/reads/events/retention work, modified reads + HistoryUpdate =>
BadHistoryOperationUnsupported with nothing sent, retention skips SampleModified, one Warning per boot.
- QuestDB integration test pinning wall-clock TTL (far-future row evicts only partitions older
than the TTL by the wall clock), with a positive control.
- Docs: Historian.md, Configuration.md, security.md, CLAUDE.md (incl. QuestDB retry duplicates,
#674.4 anonymous-readable trail with ACL off, #674.5 not implemented).
Co-Authored-By: Claude <noreply@anthropic.com>
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.
A bad keep-alive now degrades health (LastSuccessfulRead preserved) and,
once per outage, publishes BadNoCommunication (value retained) for every
subscribed ref plus a quality-only annotation on subscribed alarm
conditions. Good keep-alives and data/event notifications advance
LastSuccessfulRead, so an idle-but-alive subscription never looks dead
to the #527 watchdog. A keep-alive that recovers on the same session
re-reads the Bad refs and republishes them Good; a session that does not
come back is recovered by the watchdog's ShutdownAsync + InitializeAsync
+ re-subscribe.
Deletes the SessionReconnectHandler wiring (it retried forever in SDK
1.5.378, cloned subscriptions the driver never re-tracked and kept health
Healthy), OnReconnectComplete, TryRearmReconnect and the reconnect_*
counters (new keepalive_recovered). Teardown of a lost session skips
wire deletes and bounds CloseSession. SDK warnings reach the driver log.
Wire test reworked: restart => Bad, then watchdog-style reinit => Good.
A SIGKILLed Primary stays an unreachable-but-not-downed member until
auto-down, and the redundancy singleton usually dies with it, so the
standby's cached snapshot kept naming it Primary and nobody captured for
~30 s. DriverHostActor now holds its own ReachabilityEvent (+MemberUp)
subscription, caches the last snapshot, and excludes unreachable peers
from the historization peer-is-Primary predicate only, republishing just
the capture verdict on a reachability change. Alarm drain and the Primary
data-plane verdict are unchanged. Gated by
ContinuousHistorization:CaptureWhilePrimaryUnreachable (default true).
Tests: message-driven cases with real ReachabilityEvents (incl. a
falsification control on the drain/data-plane verdicts) plus a real
two-node cluster crash test with downing disabled.
- Historian.md: Empty samples always Bad (writer/updater/read clamp),
long-name refusal, 5 s bootstrap failure cache, AtTime after now, info-bit
masking, HistoryUpdate does NOT type-check (M-1 decision), DeleteRaw
needs both bounds, reverse Raw paging, the historian/historization metric
prefixes, and provisioning numeric-only lines qualified as Gateway.
- CLAUDE.md numeric-only lines qualified as Gateway backend.
- Stale 'sole historian' lines in DriverLifecycle, ServiceHosting and the
retired Wonderware stub; Client.CLI exit-code contract.
- ServerHistorianOptions: Endpoint/Backend XML docs untangled, Validate()
indented; Program.cs comments are backend-neutral; T10 week-test day count.
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
AdoptConfigDuringInit re-runs InitializeAsync(newConfig) and acks success, but
Calculation and Galaxy ignored the JSON there: Calculation kept its old tag
set, and Galaxy connected on its old endpoint. Calculation now rebuilds its tag
table from a config with a body (sharing AdoptConfig with ReinitializeAsync and
stopping any running timer scheduler first). Galaxy, which cannot hot-swap its
options, refuses a non-equivalent one the way ReinitializeAsync does. The actor
now sends DeltaApplied once the adopted init succeeds, so a dependency
consumer's mux interest is re-registered. Unreachable from deploys since #516.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
A Connected ApplyDelta called ReinitializeAsync and kept the actor's data and
native-alarm handles, though every driver's reinit drops the driver-side
subscriptions behind them (#630). The reconcile only re-subscribes a missing
handle, so the driver went silent until a reconnect. Release both at the
driver before the reinit and re-subscribe both in a finally. Unreachable from
deploys since #516; pinned by a two-case test, each case failing against a
different wrong fix.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
A data re-subscribe (every deploy's bulk SetDesiredSubscriptions push to a
kept driver) dropped the prior data subscription through the full
DetachSubscription, which also unhooked OnAlarmEvent and forgot the alarm
handle. On any deploy that did not respawn the driver, the alarm
subscription kept logging "established" while every event reached nobody
until a reconnect or respawn. The data path now uses DetachDataSubscription;
only a lost connection and PostStop detach both.
The #488 health-poll reconcile only looked at data, so an alarm subscribe
that failed on (re)connect gated the feed for the life of the connection.
ReconcileAlarmSubscription now re-attaches a missing handler and
re-subscribes a stale/missing alarm handle every tick.
OpcUaClient removes a half-built alarm subscription from its session when
SubscribeAlarmsAsync throws, so the new retries cannot accumulate.
Tests: actor-level data-resubscribe + reconcile-retry tests and an
end-to-end NativeAlarmFeedSurvivesDeployTests through DriverHostActor; all
three fail against the unfixed actor.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
A. #566 on a real CompactLogix (Z-35162, read-only): a class-3 connection idled 60 s past its
16 s timeout is closed at the TCP level, not with CIP 0x0107/0x0203; the next request fails on
its write (Broken pipe -> BadConnection) in 9 ms and the one after reopens. The transport already
handles this, so no production behaviour changed; the shape is pinned offline by
CipConnectionTests.A_target_that_resets_an_idle_session_... (FakeEipServer.ResetAllConnections),
proven red with a reconnect-skipping mutation. The diagnostics-only exchange tap now also sees
Forward Open replies (granted RPIs).
B. Native STRING write through the driver on Program:ES03_TemperatureControl._StrTmp: write,
read back, restored byte-exact (user-approved). Array write NOT run: the census's unreferenced
DINT[32] _SEQ_EP arrays are aliased sequencer step registers (raw L5X grep), so none qualifies.
#567 still impossible (a 128 B array / 88 B STRING never fragments).
New env-gated harness: AbCip.IntegrationTests/HardwareGate (IdleConnectionEvidenceTests,
StringWriteGateTests). Docs: gate results (hw5 section + raw output), AbCip.md, CLAUDE.md.
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
Review M1: round 1 refused only the rewritten status bits, so S:/O:/I: writes - which
never worked on libplctag because tag creation failed - would have started reaching
the PLC (outputs, status-file words) on the default transport. WriteRefusal now keys
on LibplctagLegacyName.IsTranslated: file number supplied (S/O/I, incl. bit writes
like O:0/3, refused ahead of the parent-word RMW) or status bit rewritten. Reads
unaffected. Docs/comments now true; gate doc notes R bit-number wire evidence is
non-discriminating (L1). 12 new cases fail with the round-1 predicate.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The read translation R6:0.DN -> R6:0.CON/13 made those names parse in libplctag, which
would have turned a write - previously impossible, tag creation failed - into a masked
write to the control word. LibplctagLegacyTagRuntime.WriteRefusal (via
IAbLegacyTagFactory.WriteRefusal, same plumbing as native) now refuses writes to every
rewritten status bit (R EN/EU/DN/EM/ER/UL/IN/FD, C UA) with BadNotSupported before a
runtime is created; the runtime also refuses as defence in depth. Reads stay
translated. T/C status bits libplctag parses itself keep their pre-existing behaviour.
13 new tests fail with the predicate disabled.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
libplctag 2.6.0 (bundled by libplctag 1.5.2 / NativeImport 1.0.41) pccc.c needs an
explicit file number (parse_pccc_file_num; S is only the status file when a digit
follows) and has no R-file status-bit mnemonics (sub_element_lookup: con/len/pos only;
a /bit is refused on a 6-byte element). So the canonical S:0 (the default probe),
O:0/3, I:0/0 and R6:0.DN failed with BadCommunicationError on a real MicroLogix 1400
while native read them.
LibplctagLegacyName (libplctag adapter only) now emits S2:/O0:/I1: (the native
encoder's implicit file numbers) and R6:0.CON/<bit> for status bits libplctag lacks
(R EN/EU/DN/EM/ER/UL/IN/FD, C UA), bit numbers taken from the native table. The
authored grammar is unchanged. Unit tests pin the translation per family and check,
through a model of the pccc.c parser, that the translated name addresses exactly
what the native encoder does (46 fail without the fix). Live: Z-33323 idle, reads
only - libplctag now equals native for S/O/I/R status bits; controls unchanged.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- L2: WriteWidthRefusal leaves a BOOL over a wider value to a runtime that sees the CIP
type (native): mistyped integer member -> BadTypeMismatch (as its read), 0xD3 BOOL-array
DWORD -> BadNotSupported; libplctag keeps BadNotSupported for both (size only).
- L4: direct theory over WriteWidthRefusal (1/2/4/8 widths incl LINT/ULINT/LREAL, String/Dt,
unknown size) + array/bit-selector exemptions with a non-vacuous control.
- L1: CLAUDE.md member/BIT-member writes are ab_server-proven only.
- L3: patch 0003 blind spots documented (Docker README, AbServer-Test-Fixture.md); nits.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Item 2 — controller-discovered UDT members are writable on both transports once
browse-committed and authored ReadWrite (writability is the operator's: the commit
lands AccessLevel Read with no writable key). The write names the member (one CIP
symbolic segment per member), its own type, its own bytes. BIT members are supported:
Z-35162 (read-only probe) exposes a UDT BIT member as a 1-byte 0xC1 BOOL, so the
controller applies the bit and the hidden host's other bits are never in the request.
- AbCipDriver: pre-write width check on BOTH transports (libplctag patched part of
its read buffer and sent it all): BadTypeMismatch, Bool over a wider value
BadNotSupported; nothing sent, handle kept, health untouched, warn once.
- A runtime NotSupportedException is a refusal: no longer latches Degraded.
Item 3 — whole-UDT writes refused BadNotSupported before any runtime exists, by
decision (a structure write overwrites hidden hosts + padding), documented.
ab_server patch 0003: serve member paths from dotted flat tags (UdtSeg.*), and
accept libplctag's pad byte on 1-byte writes (stock ab_server refused every
libplctag BOOL/SINT write with 0x03). New AbCipUdtMemberWriteTests (both
transports), AbCipDiscoveredMemberWriteTests, native request-byte theory, and a
browse-commit mapper pin. Docs: AbCip.md Member writes / Whole-UDT writes / Known
gaps, fixture docs, CLAUDE.md AB section.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- ReadBucketAsync: the once-per-device "sum-read chunk failed" Warning fires only after a successful
connect; a connect/backoff failure is the connect path's to report. TwinCATSumChunkWarningTests pins
it (no warning across connect failures, exactly one across two later failing sum polls; red without
the guard) plus a source guard that ReadGroupAsync builds its SumRead only via CreateSumRead.
- Docs: diagnostics live-gated via the driver harness (/hosts not exercised); TC2 costs 8 reads on the
first tick and after each reconnect, then <= 4; read counts attributed to the unit tests.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Read-only live gate on Elma presses Z35474 (TC3 3.1.4024) and Z34834 (TC2 2.11):
- Sum-read: every chunk came back BadCommunicationError. Beckhoff's
SumRead(IList<IgIoSumReadEntity>) ctor casts to IList<SumDataEntity>, which
throws InvalidCastException for a List<> (only an array survives via
covariance). The fake-client tests never built a real SumRead. New
AdsTwinCATClient.CreateSumRead passes an array; TwinCATSumReadConstructionTests
pins it (red on the List form) plus a falsifiability control on the library.
After the fix: 59 tags, status identical everywhere, values identical on every
non-moving tag, ~0.35-0.66 s vs ~2.7 s per poll; TC2 CE 2.11 answers sum reads.
- An unexpected sum chunk failure now logs one Warning per device (it was
invisible: the health message was overwritten by the next good read).
- Diagnostics: TC2 has no TwinCAT_SystemInfoVarList; fall back to .SYSTEMINFO /
.SYSTEMTASKINFOARR[1] once the TC3 name answers not-found (live: all six keys).
- #612 browse: Flat verified on TC3 (10,770 leaves; VirtualTree 1,459 strict
subset) — comment and docs updated, no load-mode option needed.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Joseph Doherty