- 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
Strict width+kind eligibility for sum-batched scalars (others read singly); latch only on ADS
1793/1794, split 1792/1797/1798 without latching; 32 KiB per-command budget and 500-item ceiling;
short sum response handled per item. Diagnostics: opt-in diagnosticsEnabled (default off), reuse the
probe's ReadState, sample after the host-state transition, JitterMs renamed HeadroomMs, compact
per-device line so many devices fit the 16-entry cap, unavailable-symbol latch cleared on reconnect.
AdminUI: min/max on sum-read max, diagnostics checkbox. Pure planner extracted and unit-tested.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Sum-read (#310): batches a poll's reads per device into sum commands capped at sumReadMaxItems,
per-item ADS errors mapped per tag, falls back to individual reads when the target refuses the
command. Diagnostics (#314): ADS state, app name, online-change count, task cycle/exec/jitter via
IDriverDiagnostics. Re-implemented against the current raw-byte read path (stranded auto/driver-gaps
commits predate it). Sum-write not ported. Unit tests only; live gate pending a route.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Removes the 'use UseNativeNotifications=false for arrays' workaround and
documents the raw-bytes array model shared by poll and notification: element
checks, STRING arrays, multi-dim flattening, 0-based publication, leading
sub-range for a shorter arrayLength, refusals (struct/UDT arrays, too long,
scalar over array), the 128 KiB native cap (BadOutOfRange), the bit-path fix,
and the 2026-10-07 read-only live gate on Z33856 / Z33733.
Found by the read-only live gate against the TwinCAT 2.11 Elma cleaners
Z33856 / Z33733:
- The Beckhoff library reports a TC2 dotted MEMBER symbol's ByteSize as if the
PLC's byte count were a bit count (STRING(80) -> 11, INT -> 1, UDINT -> 1)
while DataType.ByteSize is right (81/2/4, raw SYM_INFOBYNAMEEX says 81). The
previous commit's typeof(byte[]) read sliced by the symbol size, so
.OPC_MACHINEDATA.PROCESSSTATUS read "ready for o" at Good; the notification
width check would also have refused every numeric member. The shape now takes
the resolved type's size, and string reads go by index group/offset (or a
fresh handle for 0xF005) at that width.
- P_INITINPUT_ACTION.SLOTID is "STRING(20) (VAR_IN_OUT)" - a 4-byte reference -
but resolves to a plain STRING(20); a String tag read 21 bytes at the pointer
as text at Good. The symbol's own VAR_IN_OUT marker now classifies it
NonScalar -> BadTypeMismatch.
#507 was filed as "injection inert in v3, re-migrate onto the raw subtree".
Reading it, the retained code is not revivable: it resolves equipment from
EquipmentNode.DriverInstanceId UNION EquipmentTags, and BOTH are structurally
empty in v3 (AddressSpaceComposer always constructs EquipmentNode with a null
DriverInstanceId; DeploymentArtifact hard-codes an empty EquipmentTags set).
Removing the guard would have changed a log line and injected nothing. So it
is deleted rather than fixed, and #507 closes as superseded by /raw
browse-commit.
Removed: HandleDiscoveredNodes, PartitionDiscoveredByDeviceHost,
ShouldWarnPartition, PlansRoutingEqual, ApplyDiscoveredPlansForDriver,
_discoveredByDriver, the redeploy re-inject tail, DiscoveredNodeMapper,
DiscoveredInjection, AddressSpaceApplier.MaterialiseDiscoveredNodes,
OpcUaPublishActor.MaterialiseDiscoveredNodes, and the Runtime-local copies of
CapturingAddressSpaceBuilder/DiscoveredNode.
The connect-time discovery loop goes too (StartDiscovery, RediscoverTick,
HandleRediscoverAsync, DiscoveredNodesReady, TriggerRediscovery). With
injection gone it had no consumer, and leaving it would either dead-letter or
keep browsing real devices up to ~15x per connect to drop the result.
ITagDiscovery itself stays — the /raw browse picker drives it through
Commons/Browsing/DiscoveryDriverBrowser, which never went through the actor,
so the picker is unaffected.
deferment.md §4.4 called the 18 DiscoveryInjectionDormantV3 tests "Real —
blocked on #507". They are not: they assert an equipment-rooted graft
(EquipmentRootNodeId == "EQ-1") that v3 cannot produce, so they could never
have unskipped as written. Deleted along with DiscoveredNodeMapperTests, the
CapturingAddressSpaceBuilder tests, and the MaterialiseDiscoveredNodes tests
in AddressSpaceApplierTests/OpcUaPublishActorTests. Runtime.Tests skipped:
31 -> 13.
IHostConnectivityProbe is deliberately NOT resolved here. GetHostStatuses()
has no production call site and nothing writes a DriverHostStatus row, but the
table was re-created in the v3 initial migration, so deleting on inference
would be wrong. Split to Gitea #521 with both options costed.
CLAUDE.md, docs/drivers/{Galaxy,TwinCAT,MTConnect}.md updated — they described
the seam as dead.
Build clean; Runtime.Tests 476 passed / 13 skipped; OpcUaServer.Tests 362
passed / 4 skipped.
Adds deferment.md — a source-verified inventory of new-driver status, all 17
open issues, in-code deferrals, open live gates and plan bookkeeping. Every
claim was checked against src/ and git, not against documentation.
Headline finding: three subsystems are authored, persisted and shipped but
never executed —
* Node ACLs: IPermissionEvaluator/TriePermissionEvaluator have zero
production consumers and OtOpcUaNodeManager never references them, yet
ClusterAcls.razor authors NodeAcl rows and ConfigComposer.cs:51 ships them
in every artifact. An authored deny rule has no effect.
* IRediscoverable / IHostConnectivityProbe raise into the void (#518/#507);
nothing ever writes a DriverHostStatus row.
* DriverTypeRegistry is vestigial, so no factory passes a tier and every
driver runs Tier A with the Tier-C protections dormant.
Also records the Calculation driver as picker-visible but unauthorable
(DriverConfigModal has no case) — the "registered but unauthorable" class
recurring after the Sql picker defect — and notes that no parity test guards
DriverConfigModal/DeviceModal, which is why it survived review.
Documentation corrections (source-verified):
* ReadWriteOperations.md claimed "a denied read never hits the driver" via
four types that do not exist in src/. Bannered + struck through; a security
review reading that page would have concluded a per-node ACL gate exists.
* CLAUDE.md: the Change Detection sentence was false (DriverHost consumes
nothing); the mesh Phase 4 and Phase 5 live gates and the auto-down 1-vs-1
gate had all PASSED; the ScriptedAlarmState table was already dropped.
* driver-expansion tracking: Modbus RTU and SQL poll are merged, not
pending — its command table would have made someone rebuild two shipped
drivers in a fresh worktree.
* drivers/README.md: dead DriverTypeRegistry paragraph, retired
SystemPlatform namespace kind, missing Sql + Calculation rows, missing
Modbus RTU-over-TCP transport.
* TwinCAT.md/Galaxy.md promised an address-space rebuild that never happens.
* Historian.md gained the #491 unproven-value-capture pointer.
* IncrementalSync.md and AddressSpace.md bannered as wholesale v2-era (the
rewrite is recorded as still owed, not done here); four v2 status docs
bannered as historical; three wrong-name-for-a-live-type fixes.
Left deliberately untouched: the secrets NoOpSecretReplicator line, which
makes a security claim and needs the real behaviour identified rather than a
rename.
Joseph Doherty