- 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
M1 drop-out is a no-row Unspecified+IsRestatement update (projector case); M2 ack judged over every declared
limit; L1 ActiveAcknowledged for an already-acked new limit; L2 Bad Acked/severity carried/skipped; L3 host
end-to-end test; L4 BOOL member-by-member tests + mixed ALMD/ALMA; L5 detection requires no plain Acked.
ALMD active bit is InAlarm per Rockwell's ALMD reference; InFaulted is input health.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Detect ALMA by declared *InAlarm members; one condition per tag keyed on RawPath; severity/message from
the most severe active limit; Raise/ActiveAcknowledged/Retrigger/Clear/Acknowledge; ack writes OperAckAll.
Unit-tested over fake runtimes only (no ab_server ALMA support, Z35162 has none).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Now that ALMD transitions route, a re-subscribe (every reconnect, every alarm-set change)
started from an empty per-subscription record and re-RAISED every still-faulted alarm,
which the host projects as Active+unacked - un-acknowledging a condition the server had
just carried across the rebuild with its client ack. The record is now driver-owned and
pruned to the new set, mirroring MTConnect's _deliveredConditions.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Found while verifying item 4 of #641. The host routes a native alarm transition
on an exact ConditionId == RawPath match (DriverHostActor.ForwardNativeAlarm),
but AbCipAlarmProjection emitted "{ref}#active" and no Kind, so every ALMD
raise/clear was dropped as "no alarm condition" — and even if routed, an
Unspecified kind projects no state change. It now reports the subscribed
reference (the RawPath) and Raise/Clear. A host test pins that a decorated id
is dropped.
FOCAS has the same id shape plus a device filter keyed by host address (a
RawPath subscription polls nothing); it needs a mapping decision and is
documented in docs/drivers/FOCAS.md rather than patched here.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
FOCAS, AbLegacy, AbCip, TwinCAT, S7 and OpcUaClient orphaned the previous
probe/recycle/fixed-tree loops and clients when re-initialised on a live driver.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The libplctag-path positive control asserted 'timed out', but libplctag's internal
timeout equals the probe timeout and races the probe's own cancellation; under CPU
load it surfaces as 'ErrorTimeout' instead. Accept either libplctag stall outcome
(native never produces either: it fails at once with 'Connection lost').
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Ab.Transport.Tests: predecessor-wait counter instead of 300 ms (DeviceSessionPoolTests x2), throttle
queue/interval-park hooks instead of 50/100 ms (ForwardOpenThrottleTests x2), UnobservedTaskProbe with a
must-report control fault instead of N GC cycles (EncapsulationClientTests), re-armed keep-alive timer as
the control for the never-opened keep-alive test.
AbCip.Tests: still-polling sibling / control driver read counts instead of 300-500 ms (subscriptions x4,
alarm projection x5), structural ProbeTask==null + enabled-probe control (host probe x2), predecessor
wait (NativeAbCipLeaseReleaseTests), processed waits in the shutdown/logging tests.
AbLegacy.Tests: sibling-subscription control (Unsubscribe_halts_polling), ProbeCts==null + control.
AbCip.IntegrationTests differential safety: a post-phase control open through the same throttle instead
of 1.5-2.5 s sleeps (via a native tag init, keeping the harness read-only guard green).
Fake tag ReadCount made interlocked; CapturingLogger entries snapshotted under a lock.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- Process-wide CipConnection statics (ForwardOpenCount, Forward Close counts, RequestsSent, exchange
stats, OpenAttempts, OpenAttemptBudget) move to an instance ConnectionDiagnostics owned by each
DeviceSessionPool (and by a stand-alone CipConnection). The open-attempt budget becomes a disposable
per-DeviceKey limit (LimitOpenAttempts); the differential harness scopes one to the press under test.
- LibplctagOrphanRelease.ForceRootingForTest is gone: ReleaseIfOrphaned(tag, canReadHandles) overload.
- A connected reply with general 0x01 / extended 0x0107 or 0x0203 (target no longer holds the class-3
connection, TCP still up) retires the session at once; the next send reopens through the throttle.
- New tests: dispose during RegisterSession, abandoned-open observer (falsified), scheduler-dispose-throws
guard (DeviceSessionPool.CloseAsync), release-in-background with a shared open in flight, per-device
limit scoping, CIP-close recycle (request + keep-alive + negative control).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
#570
- STRING: the built-in 88-byte Logix STRING holds 82 characters (LEN + DATA[82] + 2 pad), not 84; the
write still sends the whole 88-byte structure and a read never decodes the pad as characters.
- Mistype churn: a type refusal (CIP 0xFF/0x2107) on the existence read no longer throws from
InitializeAsync, so the runtime is not disposed/re-created (and re-Forward-Opened) every poll; the driver
also keeps a runtime that throws TypeMismatch from init and records the device as reachable.
- Malformed tag name: a TagPath that does not parse, or a name the CIP symbolic encoder refuses (now also
non-ASCII, empty member, >255-char member, unterminated subscript), is AbCipTagConfigurationException ->
per-tag BadConfigurationError (named const in AbCipStatusMapper), warned once, never feeding the device
backoff or health; siblings keep reading. A malformed probe tag no longer feeds the backoff either.
- Micro800 BYTE/WORD/LWORD (0xD1/0xD2/0xD4) are type-checked as integers of their width: REAL/LREAL or a
narrower integer over LWORD is TypeMismatch, not decoded garbage.
#579
- ConnectionLease.ReleaseInBackground: one non-blocking release shape for both native AB runtimes. The
AbCip runtime's Dispose no longer waits up to 2 s under the per-tag lock; the pool still registers the
close synchronously so a re-create cannot overlap it. Offline soak tests (25 cycles, AbCip + AbLegacy)
prove no leaked connection; FakeEipServer gains OpenConnections.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
#572: listing continues at max(instance in page)+1 (no ascending-order assumption, no-progress guard kept);
browsePageDelayMs (default 5 ms) paces pages; DiscoverAsync reads templates through one batch reader
(IAbCipTemplateReaderFactory.CreateBatch) holding one lease.
#575: differential harness reports a same-status template refusal as an equal refusal; offline test pins the
open-attempt budget without relying on the abort ending the phase.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
HandleOf cast the reflected nativeTagHandle with (int) and was called
inside the runtimes' catch blocks, so a libplctag bump that retyped the
field would replace every create failure with an InvalidCastException.
The field is now accepted only if it is still an int (otherwise
CanReadHandles is false and orphans are rooted), and HandleOf never
throws. Both projects pin the field type explicitly.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
A native TypeMismatch (read status, write gate, or CIP 0xFF/0x2107) used
to evict the runtime and degrade health on every poll; for a sole lease
holder that meant Forward Close + Forward Open per poll, and an all-
mismatched driver tripped the comms-loss watchdog. It now reports
BadTypeMismatch, keeps the handle, leaves health alone and warns once per
tag per instance — reads, whole-UDT reads and writes, plus the libplctag
width check. Tests (red against the pre-fix driver): single create over N
polls, unchanged health, one warning, and one Forward Open / zero Forward
Close over the real native runtime against FakeCipTarget. AbLegacy has no
TypeMismatch path (its native runtime has no type check).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The old AdminUI cannot author the per-driver transport key (#576), so the
'pin before upgrading' recipe had no working path. A node-level appsetting
(env Drivers__AbCip__DefaultTransport) now supplies the default for AbCip
drivers with no key: explicit key > node default > compiled Native. Bound
and validated unconditionally (bad value fails host start); the driver
factory and the Test Connect probe both read it so they agree. AbCip.md
upgrade recipe rewritten around the key; Configuration.md documents it.
Also documents first-wins for AllowPacking/probe and host-alias throttles
(final review M6) and moves the status-bit note out of AbCip.md (M5).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Native is the default, so a locally refused write must not look like a comms fault.
- AbLegacy: an AbTransportException with AbStatus.Unsupported (status-bit sub-element writes, PLC-5
non-N reads, all PLC-5 writes; libplctag's ErrorUnsupported maps here too) now returns
BadNotSupported on both the read and the write path (incl. the bit-RMW path). The tag handle is
not evicted and driver health is not touched. A native runtime whose init read is refused locally
is CACHED rather than disposed, so a poll of a refused tag does not re-create (and re-lease the
pooled connection) every cycle.
- AbCip: the same mapping on the write path and both read paths (single + whole-UDT).
- Uses the existing named BadNotSupported constants (StatusCodeParityTests guard).
- Tests (falsified by disabling the mapping, and separately the keep-on-refusal): status-bit
writes and PLC-5 read/write through the driver over the native runtime — BadNotSupported, zero
wire requests, one create, health unchanged; AbCip refused read/write via a refusing fake plus a
control that a non-refusal failure still evicts and degrades.
- Docs/CLAUDE.md: BadNotSupported; #571 known-gap wording removed.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- I1: the upgrade restart itself moves every no-key AbCip/AbLegacy driver to Native (every process
start constructs drivers, incl. boot-from-cache). Docs + CLAUDE.md now say so and tell operators
to set "transport": "Libplctag" BEFORE upgrading (older builds ignore the unknown key).
- I2: AbLegacy release note leads with the status-bit write refusal (T4:0.DN, C5:0.CU, R6:0.EN, ...)
on defaulted SLC/MicroLogix drivers and the fallback. The real client status is
BadCommunicationError, not BadNotSupported (the driver's write catch-all maps the runtime's
AbTransportException like any transport failure, as #571 does for PLC-5), with handle eviction
and Degraded health; pinned by a driver-level test (no 0xAA write on the wire, with a positive
control). ST string byte order stated as unverified. Also corrects the docs' "T4:0/DN" examples:
the driver's address grammar is "T4:0.DN" ("/DN" is a malformed address).
- I3: DriverProbeHandshakeE2eTests' two AbCip probe tests are a [Theory] over Native and
Libplctag. Run against ab_server controllogix: all 4 rows pass with identical exact messages.
- M1: documented (docs + resolver XML doc): the AdminUI merges only the probed device, so a
mixed-family defaulted AbLegacy driver can probe Native while running Libplctag.
- M2: factory ParseEnum rejects undefined integer strings ("7") via Enum.IsDefined (both drivers).
- M3: AbCip driver-level bad value reads "AB CIP config in '<id>' has unknown Transport ..."; the
named constant is gone (tagName: null now means driver-level).
- M4: the explicit-Native limited-family Warning is once per instance, not per (re)init.
- Nit: EffectiveTransport docs note that injected factories bypass it.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Task 22 (spec section 8 P5), with the controller rulings that exclude PLC-5 and LogixPccc.
- Transport is nullable on both option records; null (key absent) means "use the default" and is
never serialized. Factory DTO parse: absent -> null; a bad value still fails via ParseEnum.
- One resolver per driver (AbCipTransportResolver / AbLegacyTransportResolver), used by the driver
constructor, the Test Connect probe and (through the driver) the CLI.
AbCip: null -> Native. AbLegacy: null -> Native unless any device is Plc5 or LogixPccc, then the
whole driver resolves to Libplctag. Explicit values always win; explicit Native with a
Plc5/LogixPccc device logs one Warning at init.
- Init log shows configured vs effective, e.g. transport=Native (default).
- AdminUI forms: "Default (...)" / "Native (managed)" / "libplctag (fallback)". Default omits the
key on save (reverses Task 19's explicit re-emit, which would have pinned every edited driver).
- CLIs: --transport default|native|libplctag, default "default" via the resolver, so
--plc-type Plc5 with no --transport runs libplctag.
- Tests pinned to Libplctag where a default-path runtime was created: found by instrumenting the
native factories with the current xUnit test name (one unit test, AbLegacyReinitConfigAdoption;
plus the two fixture-gated AbCip probe E2E tests whose exact messages were proven on libplctag).
TransportMatrix and the differential harness already pass explicit transports.
- Switch/resolver/CLI/form tests are falsified by mutating the resolver (default -> Libplctag,
exclusion removed, AbLegacy default -> Libplctag): each mutation turns them red.
- Replaces the inline role-name literal in AbCipDriverFactoryExtensions' ParseEnum call with a named
constant; RoleAuthorityGuardTests was already red on the base commit for that line.
- Docs: AbCip.md / AbLegacy.md default + release note; CLAUDE.md AB section.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
M2: after plc_tag_destroy, the release writes 0 back to the wrapper's nativeTagHandle, so a repeat release is a no-op instead of touching a destroyed id. The runtimes keep the destroyed handle for tests and diagnostics.
M1: the rooting fallback is now described accurately, as an unbounded leak (one native tag per failed create), not a bounded one. A test seam (ForceRootingForTest) pins that the fallback roots the tag and destroys nothing.
Both pins are red with their line removed. The orphan tests share a non-parallel collection, because the counters and the seam are process-wide.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The T21 press pass 1 test host died at exit with "A callback was made on a garbage
collected delegate of type ...plctag+callback_func_ex::Invoke". The cause is in
libplctag.NET 1.5.2. When a tag's create fails, for example with NotFound,
InitializeAsync throws with the callback still registered. Dispose() destroys a tag
only if it is initialised, so the native tag outlives its wrapper. The GC then frees
the delegate, and libplctag's atexit plc_tag_shutdown raises DESTROYED into it.
Reproduced against ab_server: the production LibplctagTagRuntime with a NotFound tag
exits 134 with that exact message, and exits 0 with this fix.
A timed-out create unregisters its callback but never destroys the handle either,
so that native tag keeps reconnecting for the life of the process.
The fix adds LibplctagOrphanRelease (AbCip and AbLegacy). After a failed
initialise/read/write that leaves the tag uninitialised, it reads the handle through
the pinned wrapper's private fields, unregisters the callback and destroys the tag.
If those fields cannot be read, it roots the tag for the life of the process
instead. It is applied in both tag runtimes, the symbol-listing reader and the
template reader. GetStatus keeps the status the tag held before it was destroyed.
Pins: offline refused-connection tests in AbCip.Tests and AbLegacy.Tests, a live
NotFound test on ab_server, and a reflection-shape pin. All go red with the release
disabled. The differential harness also asserts that no orphan had to be rooted.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- AbCip/AbLegacy driver forms gain a Transport InputSelect; FromOptions/ToOptions now carry
Transport, so saving any other field no longer silently reverts Native to libplctag.
- Both drivers log the constructed transport once per init.
- AbCip factory now takes the host ILoggerFactory (it ran on NullLogger in production, hiding
every AbCip log line); DriverFactoryBootstrap passes it.
- Gate results: AdminUI /run (T19) native, inverted (dead port) and libplctag legs.
The libplctag adapters assigned Tag.Path straight from the device's parsed
CipPath. A device address with no route (ab://host:44818/ - the normal
Micro800 form, and a MicroLogix with no route) parses to "", and libplctag
rejects an empty path attribute with ErrorBadData; omitting the attribute
(null) is what it accepts. So Micro800 could not connect on the default
libplctag transport.
This predates the native transport work and exists on master.
Add an internal LibplctagPath.Normalize helper per driver project (blank ->
null) and route all four Tag constructions through it (AbCip tag runtime,
symbol-list enumerator, template reader; AbLegacy tag runtime). The runtime
tag construction is extracted to an internal BuildTag so tests can inspect
Tag.Path without connecting. Tests fail with Normalize reverted to identity.
Update the Micro800 smoke-test comment: both transports are expected to pass.
Scheduler tests (exclusive mid-queue and at head) and a template-reader test that
genuinely queues a Read Template behind a small read; bounded QueuedCount wait
replaces the fixed delay. Falsified: removing exclusive from the reader turns the
reader test red; removing the Exclusive handling in RequestScheduler turns all three red.
libplctag decodes whatever bytes the controller returns as the authored type and never
checks the CIP type code. Live read-only check on a production press: WW_ActualVacuum is a
REAL (L5X + the controller's symbol table agree) but the legacy Kepware export in the
ignitionoee repo types it Short; read as INT it returned Good -17346 while the real value
was 5.37. A scalar atomic read (not an array, not a bit-in-DINT) whose buffer size is not
the authored type's width now reads BadTypeMismatch with a warning naming both. Widths
observed live: SINT/BOOL 1, INT 2, DINT/REAL 4, LINT 8. IAbCipTagRuntime.GetSize() is a
default-interface member (-1 = unknown, never checked). Same-width mismatches (DINT vs
REAL) stay undetectable without the type code libplctag strips.
Live read-only check against a production CompactLogix press: Program:UN01_Press._ModeNames
(STR0016[32], 4 elements requested) returned an 80-byte buffer with libplctag.NET 1.5.2's
ElementSize unset. The driver fell back to the static 88-byte STRING stride, read element
1 past the buffer, and the whole read failed (ErrorOutOfBounds -> BadCommunicationError).
When the buffer divides evenly by the element count, that quotient is now the stride;
the read returns [undefined, Production, Maintenance, Manual] as the controller holds.
Live read-only check against a production CompactLogix press: with one nonexistent tag
first in the read list, libplctag's create threw LibPlcTagException("ErrorNotFound"); the
driver counted it as a failed Forward-Open, opened the device's 05/STAB-8 connect-backoff
window, and every other cold tag on the device - all real (WW_InCycle, WW_ActualPress,
WW_WorkOrderNum) - read BadCommunicationError. In steady polling the bad tag re-opens
the window each attempt, so siblings ordered after it may never connect.
- A create that fails with a "controller answered" status (NotFound/NoMatch/BadDevice,
the probe's existing reachable classification) records backoff SUCCESS, not failure.
Genuine connection failures still open the window (falsification control test).
- Read exceptions map through the libplctag Status they carry: unknown tag ->
BadNodeIdUnknown, decode past the buffer -> BadOutOfRange, timeout -> BadTimeout,
instead of a blanket BadCommunicationError. One status-name parser
(AbCipStatusMapper.TryGetStatus) now serves both the read path and the probe.
Live read-only check: a production CompactLogix lists the module tag ABB_OmniCore:I in
@tags and libplctag reads ABB_OmniCore:I.ConnectionFaulted without complaint, but the
driver refused the path as malformed (identifier rule had no colon) and reported the
tag BadCommunicationError. Colon-separated identifier/slot parts are now legal in the
controller-scope base segment only (never past it, never under Program: scope).
Live read-only check against production CompactLogix 5069-L320ERS2 presses:
- The controller @tags listing names each program (Program:UN01_Press, a system symbol)
but none of its tags; those are listed only by Program:<name>.@tags. The enumerator read
@tags alone, so every program-scoped tag was unbrowseable — including the PackML state
(Program:UN01_Press.Out_eState) and all 51 alarm bits the Ignition project reads. The
enumerator now reads each program's listing and decodes it with that program as scope;
an unreadable program listing is skipped, not fatal.
- The Symbol Object decoder ignored the dimension bits + dim words, so every discovered
array (DINT[32], REAL[32], STRING[50], UDT[23] on the two controllers checked) browsed as
a scalar. IsArray/ElementCount are now populated (multi-dim flattened). A 1-D single
element entry stays scalar: ab_server reports every scalar that way, a real controller
sets no dimension bits on scalars.
Pinned by entries captured off the controllers (CipSymbolObjectRealControllerCaptureTests,
AbCipProgramScopeEnumerationTests).
Live read-only check against production CompactLogix 5069-L320ERS2 rev 34.11 presses
(Z-35162 / 10.209.70.160): every @udt/<id> template the controller returned decoded to
null, so controller-discovered UDTs never fanned out. The decoder assumed a 12-byte
header led by the member count and [info][array][offset] blocks with ';'-terminated
names; libplctag actually returns a 14-byte header (u16 id, u32 def words, u32 instance
size, u16 member count, u16 handle), [info][type][offset] blocks, and NUL-terminated
names after a 'Name;<tail>' type name. All three test builders restated the old
assumption, so the unit suite agreed with itself (the #468 trap again); they now share a
TemplateBufferBuilder pinned by real captures (CipTemplateObjectWireCaptureTests).
Discovery follow-ons that the working decoder exposed:
- STRING (and user string types, LEN DINT + DATA SINT[n]) browse as one String variable,
top-level and nested, not as a LEN/DATA folder.
- Controller-generated members (ZZZZZZZZZZ* BOOL hosts, __* AOI backing) are not browsed.
- A UDT array is not fanned out into element-free Tag.Member paths.
Joseph Doherty