Removes the tag-set drift detector shipped in e77c8a35. The design was sound
-- the tautology drivers were correctly gated out, and the structurally
undetectable "vanished" direction was declared rather than faked -- but none of
that is the objection. The feature browsed real plant equipment on a recurring
timer, at a frequency no operator could configure (the interval was a
constructor parameter with no appsettings key), and that outbound traffic was
never once observed against a real PLC, CNC or MTConnect Agent.
Removed: TagSetDrift/TagSetDriftDetector; DriverInstanceActor's drift timer,
tick message, Props/ctor parameter, gate, handler and leaf-collector;
ITagDiscovery.AuthoredDiscoveryRefs + .DiscoveryStreamIncludesAuthoredTags and
their four implementations; 14 tests.
Kept: ITagDiscovery.SupportsOnlineDiscovery (it predates this and drives the
universal browse picker), and the whole IRediscoverable consumption from
09a401b8 -- the driver tells us, we do not poll.
CONSEQUENCE, deliberately accepted: AbCip and FOCAS browse a live backend but
implement no IRediscoverable, so they now have NO tag-change signal at all -- a
PLC re-download is invisible until someone re-browses by hand. Recorded in
CLAUDE.md so the next reader does not have to rediscover it, along with the
shape to reach for if that coverage is wanted back (event-driven, or triggered
by a reconnect/deploy, not a wall-clock timer).
Runtime.Tests 476 pass / 13 skipped (skip set unchanged); FOCAS 275, TwinCAT
192, MTConnect 491, AbCip 342, Core.Abstractions 266 all green.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
The second thing #516/§8.2 deliberately did not build. The original objection
stands — Modbus, S7, MQTT, AbLegacy and Sql echo authored config from
DiscoverAsync, so diffing discovered against authored is a tautology for them
— but it is now ENCODED rather than used as a reason not to build.
The discriminator already existed: ITagDiscovery.SupportsOnlineDiscovery is
documented as "enumerates the tag set from the live backend rather than
replaying pre-declared/authored tags", and it separates the fleet cleanly —
FOCAS, TwinCAT, MTConnect and AbCip true; the five config-echo drivers
explicitly false. The check runs only for a driver that is
SupportsOnlineDiscovery AND reports the new AuthoredDiscoveryRefs. That is
nullable rather than empty-by-default on purpose: an empty collection
legitimately means "nothing authored, everything discovered is new", so
conflating the two would report total drift for a driver that never opted in.
Where the value is: AbCip and FOCAS browse a live backend but implement no
IRediscoverable, so before this they had no change signal at all. A periodic
compare is the only way to notice a PLC re-download.
A finding that changed the design: FOCAS, TwinCAT and AbCip all re-emit their
authored tags into the same DiscoverAsync stream as device-derived ones, so
the browse picker can show an operator their existing tags. Discovered is
therefore always a superset of authored, and a VANISHED tag can never appear
missing — one whole direction is structurally undetectable for three of the
four. Shipping a Vanished list that is permanently empty for them would have
been the half-inert seam this whole exercise removes. So the driver declares
DiscoveryStreamIncludesAuthoredTags, the detector does not compute the
undetectable half, and the operator message says "missing-tag detection
unavailable for this driver" rather than letting the absence of a missing-tag
clause read as reassurance. MTConnect is the only driver where both directions
work — its stream is purely probe-model-derived.
Behaviour: a failed browse is not drift (an unreachable device would otherwise
report every authored tag as vanished); a truncated capture is skipped for the
same reason; an unchanged drift is reported once rather than re-stamping its
timestamp; drift that resolves clears the prompt. Interval defaults to 5
minutes — it browses a real device, and a tag set changing is an engineering
event, not a runtime one. It reuses the Stage-2 surfacing, raising the same
/hosts re-browse prompt, and never rebuilds the served address space.
Comparison logic is a pure, separately-tested type rather than actor-inline.
14 new tests. The gate was verified load-bearing by deleting the
SupportsOnlineDiscovery half: the tautology-driver test goes red, and it
asserts discovery was never invoked rather than merely "no prompt raised",
which would have passed for the wrong reason if the timer never fired.
Full suite green except the same three pre-existing fixture-gated integration
suites, identical counts.
Task 3/4/5: SupportsOnlineDiscovery => true on AbCipDriver, TwinCATDriver, FocasDriver
(their device enumeration is real, config-gated on EnableControllerBrowse / FixedTree.Enabled
which PatchForBrowse guarantees at open). One gate fact per driver test project.
- CapabilityInvoker: 3 methods that implement IDriverCapabilityInvoker now use
<inheritdoc /> instead of duplicating the interface docs (MissingInheritDoc).
- TwinCAT NativeRegistration ctor: added the 8 missing <param> tags (MissingParam).
- Stripped the arch-review bookkeeping IDs STAB-1 (IS7Plc, S7Driver) + STAB-2
(TwinCATDriver x4) from comments, keeping the descriptive text.
Left the other 86 flagged items untouched — they are checker false positives on
legitimate technical content: interface-implemented events / IEqualityComparer /
IDisposable members whose <inheritdoc/> IS correct (10 InheritDocMisused), and domain
terms the heuristic misreads as tracking IDs (IEEE-754, S7-1200/300/400/1500, PLC-5,
D2-260, S7/Melsec memory addresses, OPC UA Part 9, phase-N design-doc filename refs,
UNS level-N descriptions, and prose like 'the #1 bug source' / failover 'pick #3').
Native ADS notifications (the default subscribe mode) were stored as opaque handles
with no record of the symbol/type/interval/handler needed to replay. On a client swap
(EnsureConnectedAsync building a fresh client after a drop) the notifications were
silently orphaned — no Bad status, no error, pushes just stopped until redeploy.
Compounding: the IsConnected fast-path keys on AMS-port state, not wire liveness, and
a probe failure only transitioned state without recycling the dead client.
Fix:
- Store REPLAYABLE INTENT: NativeRegistration (symbol/type/bit/interval/onChange +
swappable live handle) hung off DeviceState.NativeRegistrations, populated by
SubscribeAsync via RegisterNotificationAsync (under ConnectGate).
- Split EnsureConnectedAsync into a gate wrapper + EnsureConnectedUnderGateAsync core;
when the core installs a NEW client it replays every stored intent onto it and swaps
the live handle (disposing the dead one). Register + replay both run under ConnectGate
so they can't race.
- Probe loop: on a wire-probe failure (false or throw) RecycleClientAsync disposes+nulls
the client so the next tick rebuilds + replays — closes the fast-path-keys-on-port-state
compounding bug.
No TwinCAT docker fixture exists (integration needs a real TC3 XAR), so the fake-client
unit tests are the authoritative coverage:
- 4 new guards in TwinCATReconnectReplayTests (replay-onto-fresh-client + push reaches
OnDataChange + old handle disposed; replay-all-tags; unsubscribe-after-reconnect stops
replaying; probe-failure recycles+rebuilds).
- Full TwinCAT unit suite 174/174 green; full solution builds 0 errors.
Adds <summary>/<param>/<returns>/<inheritdoc> where missing and removes
project bookkeeping IDs (task/tracking refs) from shipped code comments,
so the docs read cleanly and CommentChecker is quiet except for known
false positives (PLC/protocol terms, event/IEqualityComparer inheritdoc).
Doc/comment-only; no logic changed; solution builds clean.
Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.
- Driver.TwinCAT-004: corrected the IEC time-type inline comments;
documented that the driver currently surfaces them as raw UInt32
counters.
- Driver.TwinCAT-006: ResolveHost returns a documented UnresolvedHost
sentinel when no devices are configured instead of returning the
logical DriverInstanceId (which never matches GetHostStatuses).
- Driver.TwinCAT-014: wired Probe.Timeout into the probe-loop call and
added a NotificationMaxDelayMs config knob threaded through
AddNotificationAsync.
- Driver.TwinCAT-015: Dispose() runs a genuinely synchronous teardown
with bounded waits (no sync-over-async deadlock pattern).
- Driver.TwinCAT-016: pinned the Structure-tag rejection and the
probe-loop vs read disposal race with regression tests.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
GetMemoryFootprint now returns tagsByName * 256 + nativeSubs * 512 bytes
instead of a hard-coded 0; document that the stream-and-discard symbol
browse leaves no flushable cache so FlushOptionalCachesAsync is a
deliberate no-op.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Confirm AdsErrorCode values from Beckhoff.TwinCAT.Ads 7.0.172 and rewrite
MapAdsError with 20 explicit cases. Fix critical bug: AdsSymbolVersionChanged
was 0x0702 (DeviceInvalidGroup) but DeviceSymbolVersionInvalid is 1809
(0x0711); correct constant and all comments. Add BadOutOfService for
DeviceNotReady and BadInvalidState for DeviceInvalidState/PLC-in-Config.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Swap _devices and _tagsByName to ConcurrentDictionary so ShutdownAsync
Clear() no longer races concurrent TryGetValue calls; store ProbeTask
on DeviceState and await it in ShutdownAsync before disposing the client
and gate, eliminating the probe-disposal race.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Driver.TwinCAT-001 — InitializeAsync/ReinitializeAsync ignored driverConfigJson.
Extracted the DTO-to-options parse into a shared TwinCATDriverFactoryExtensions.ParseOptions;
InitializeAsync now re-parses driverConfigJson into a mutable _options field, so a config
generation pushed via ReinitializeAsync (added/removed devices, tags, probe settings) is
actually applied at runtime.
Driver.TwinCAT-002 — LInt/ULInt narrowed to Int32. ToDriverDataType now maps LInt to Int64,
ULInt to UInt64, UDInt to UInt32, UInt/USInt to UInt16, Int/SInt to Int16, and the IEC
TIME/DATE/DT/TOD types to UInt32 (their raw UDINT counter). Removed the stale "Int64 gap"
comment — no truncation or sign flips at the OPC UA encode layer.
Driver.TwinCAT-007 — EnsureConnectedAsync was not thread-safe. Connect/reconnect is now
serialized per device by a SemaphoreSlim (DeviceState.ConnectGate) with a double-checked
connect, mirroring the S7 driver. Concurrent read/write/probe callers can no longer leak a
client or race a create-vs-dispose.
Driver.TwinCAT-008 — native ADS notification callbacks ran driver logic on the AMS router
thread. AdsTwinCATClient now enqueues AdsNotificationEx callbacks onto a bounded Channel
drained by a dedicated managed task; the router-thread callback only does a non-blocking
TryWrite, so a slow consumer cannot stall ADS notification delivery process-wide.
Driver.TwinCAT-013 — TwinCATDriver did not implement IRediscoverable. The driver now
implements IRediscoverable; AdsTwinCATClient detects ADS 0x0702 (symbol-version-changed) on
read/write paths and raises OnSymbolVersionChanged, which the driver forwards as
OnRediscoveryNeeded so Core rebuilds the address space after a PLC program re-download.
Adds TwinCATHighFindingsRegressionTests covering all five fixes; updates the data-type
mapping assertion in TwinCATDriverTests. TwinCAT driver builds clean; 119 tests pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Group all 69 projects into category subfolders under src/ and tests/ so the
Rider Solution Explorer mirrors the module structure. Folders: Core, Server,
Drivers (with a nested Driver CLIs subfolder), Client, Tooling.
- Move every project folder on disk with git mv (history preserved as renames).
- Recompute relative paths in 57 .csproj files: cross-category ProjectReferences,
the lib/ HintPath+None refs in Driver.Historian.Wonderware, and the external
mxaccessgw refs in Driver.Galaxy and its test project.
- Rebuild ZB.MOM.WW.OtOpcUa.slnx with nested solution folders.
- Re-prefix project paths in functional scripts (e2e, compliance, smoke SQL,
integration, install).
Build green (0 errors); unit tests pass. Docs left for a separate pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty