All three legs pass against the patched AbCip fixture: the edit modal and the
manual-entry grid both browse the live nine-tag symbol table, and an unreachable
device degrades to the graceful error chip while the modal still saves.
The gate also found a defect unrelated to this change and filed it as #539: the
AbCip discovery path (LibplctagTagEnumerator, LibplctagTemplateReader) passes
libplctag the bare host, so an authored non-default EtherNet/IP port is dropped
and the browse reaches whatever answers on 44818 — #534's defect surviving in the
discovery half. Discovered because the first negative-leg endpoint differed from
the fixture only by port, which never reached the wire.
Records the outcome in the design doc §6 (including the stale-open race the
review found and fixed in both modals), closes the follow-up in the tracking
doc and the universal-browser plan, and registers RawBrowseModal's shared
race shape in deferment.md §0.1 as the deliberate leftover.
A browse-committed AB CIP / TwinCAT / FOCAS tag bound with its model's DEFAULT
data type, not the one the device reported. A browsed REAL committed as
`{"tagPath":"Pump_1_Speed","dataType":"DInt"}` — and those three drivers decode
the wire bytes by that field, not by the raw row's OPC UA DataType — so the tag
read four bytes of a float through an integer decoder and published a plausible
wrong number with no error raised anywhere. FOCAS was missed when #536 was filed.
The type is CARRIED, not derived. Reverse-mapping the leaf's driver-agnostic
DriverDataType looks like the smaller fix and is wrong: SInt/Int/DInt/USInt/UInt
all collapse into Int32 on the way out of the driver, so that version would bind
a 16-bit INT as a 32-bit DINT while appearing to fix the REAL. Drivers now state
their own type name on DriverAttributeInfo.NativeDataType, which reaches the
picker as AttributeInfo.AddressFields["dataType"] and the commit mapper from
there. A leaf that states nothing keeps the model default — the pre-#536
behaviour, kept deliberately as the fallback rather than a guess.
Numeric strings are refused before parsing: Enum.TryParse accepts "9" for any
enum and Enum.IsDefined then confirms it, so an unguarded parse would bind a tag
to a type nobody named. A test caught this in the first version of the guard.
--- and the other half, which the fixture was hiding ---
Test Connect on a device with NO authored tags — every AB CIP device at the
moment an operator first presses the button — reported "CIP handshake failed"
against a healthy controller. That was written down as a fixture limitation
("ab_server doesn't implement @raw_cpu_type"). Both halves of that were wrong:
* @raw_cpu_type is not a libplctag special tag at all (only @raw, @tags and
@udt/ are), so it goes out as an ordinary symbolic name that no controller
defines, and the controller's "tag does not exist" IS the successful answer.
* ab_server answered an unresolvable tag path with CIP 0x03 where a Logix
controller answers 0x04 — ErrorBadParam vs ErrorNotFound, which the probe
classifies oppositely. Fixed in vendored patch 0002.
* With the fixture then telling the truth, the real defect surfaced:
AbCipDriverProbe.IsReachableException matched the native C status spellings
("STATUS_NOT_FOUND"), but libplctag.NET throws with the MANAGED enum name
("ErrorNotFound"). Those substrings can never match, so the reachable
classification could not fire on the exception path — which is the path every
no-authored-tags probe takes. This was failing on real hardware too, not just
against the sim. It now recovers the Status and defers to IsReachableStatus,
so there is one classification rather than two that can drift.
Rejected: switching the fallback to @tags. libplctag builds a tag-listing tag
with NO network I/O, so it reports OK against any TCP listener — measured green
against a Mosquitto broker.
Verification: full solution suite green. Falsification runs confirm exactly the
intended tests go red — 9 for the type carry, 3 (the reachable statuses only) for
the probe classification. Live on docker-dev: browse-committed TestString/
Motor_Run/TestSINT now store String/Bool/SInt, alongside last session's
Pump_1_Speed still holding the wrong DInt. TestSINT is the falsifier — its row
DataType is Int32, identical to TestDINT's, so no reverse map could have produced
"SInt".
Known consequence: pre-existing browse-committed tags keep their wrong dataType;
the fix applies to new commits only.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
The AbCip controller browse could never be verified end to end: libplctag's
ab_server answers CIP service 0x55 (Get Instance Attribute List) on the Symbol
Object class with "unsupported", so the `@tags` walk had no backend. #468's own
definition of done offered a sim that serves `@tags` as an alternative to real
hardware; this is that.
The fixture now applies a vendored patch teaching ab_server to serve the Symbol
Object listing, with partial-transfer paging. Correctness is checked against
libplctag's own `list_tags_logix` rather than against our decoder — our decoder
is the thing under test, so its agreement would prove nothing. The clone is also
pinned to a concrete tag: the Dockerfile called `--branch release` "pinned" while
tracking a branch that moves.
That immediately exposed a real defect. CipSymbolObjectDecoder advanced to an
even byte boundary after each symbol name, but entries are packed with no
padding — libplctag walks them by sizeof(entry) + string_len, and a captured
reply confirms it. Any odd-length name therefore desynchronised every entry
behind it, and odd-length names are ordinary. In the live browse below,
`Motor_Run` is 9 bytes and first on the wire, so the old decoder would have
shown that one tag and silently dropped the other eight.
Every existing multi-entry test passed throughout, because the test builder
padded exactly as the decoder did: the two agreed with each other and neither
agreed with a controller. The builder no longer pads, and the layout is pinned
by a captured reply (CipSymbolObjectWireCaptureTests) instead of by a second
statement of the assumption. Restoring the alignment step reddens exactly the
three new tests and none of the 29 others.
Live gate on docker-dev, all three of #468's criteria:
- populated tree — all nine seeded tags render as leaves, in wire order
- refresh re-captures
- leaf commit — Pump_1_Speed + TestDINT saved with their CIP tag paths
The gate also surfaced two things it was not asked about: browse-commit drops
the discovered data type, so a browsed REAL commits as a DINT and the driver
decodes it as one (filed as #536), and Test Connect fails against this fixture
regardless of the device because it probes `@raw_cpu_type` (documented).
TwinCAT and FOCAS still have no browsable backend; #468's AbCip half is closed,
theirs is not.
Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
Live-verified on docker-dev: AbCip picker renders Browse button (full CanBrowse chain), clicking
it runs the universal-browser capture in production (central-2 logs) with PatchForBrowse
demonstrably applied (@tags walk ran without the authored config setting EnableControllerBrowse);
error surfaces gracefully. Modbus picker shows NO Browse button (negative). Populated tree-render
is fixture-blocked — ab_server returns ErrorUnsupported for the controller @tags walk (test sim
limitation, not a code defect). Two follow-ups recorded: (1) full tree-render needs a symbol-browse
capable AB backend; (2) driver-page pickers don't pass live config to the picker body.
Joseph Doherty