Health contract: an MTConnectError document (NO_DEVICE, INVALID_REQUEST, ...) is the
Agent answering. The parsers now mark such an InvalidDataException
(MTConnectXml.IsAgentRefusal - the type is sealed, so a Data marker, every other
handler unchanged); ReadAsync reports the batch Bad but does not degrade the read
path, advances LastSuccessfulRead, clears a prior read degradation and warns once
per distinct refusal. An unparseable answer stays a comms fault.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The driver logged and surfaced the raw AgentUri (which may carry user:pass@) as
HostName (the /hosts key), in ~20 log lines and in exception messages that reach
DriverHealth.LastError, and the client's request-URI messages (timeouts, stream
end, not-a-stream, framing) embedded it too - while the Test-Connect probe
deliberately redacted it. New MTConnectUriRedaction (user-info, and for the
configured string its query, removed; a clean URI is unchanged so host keys do
not move); the driver computes its display form once per options document.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The connectivity probe parsed the full /probe device model every 5 s and discarded
it. It now calls a new IMTConnectAgentClient.PingAsync: one GET /probe read with
ResponseHeadersRead and a status check; the body is dropped unread. Same failure
surface as ProbeAsync (the default implementation delegates to it). The probe-tick
tests now count pings and pin that no tick issues a full /probe; the shutdown
test's absence assertion gained a positive control.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Writes were one POST per slot although the Agent's PUT surface accepts several
id=value pairs. The slots surviving the local refusals now go out as one
WriteObservationsAsync(device, pairs) per device (new IMTConnectAgentClient method;
the default loops the single-pair call). A batch closes at another device or a
repeated DataItem so same-item writes keep request order; a refused multi-slot
request is retried per slot so one refused DataItem costs only its own slot.
Health contract: any Agent answer (accepted or refused) advances
LastSuccessfulRead with the state following the read / stream flags.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Subscription throughput was hard-capped at SampleCount / SampleIntervalMs with no
lag detection: a machine producing more fell behind the ring buffer forever,
re-baselining every buffer-length with every value backlog-stale.
- The parser carries the header's optional lastSequence; each chunk measures
lag = lastSequence + 1 - nextSequence and whether it was saturated (full count).
- Three consecutive saturated chunks with a positive (or unknown) lag reopen the
stream at the cursor reached with count doubled, up to 16x SampleCount (max
65536), through a new IMTConnectAgentClient.SampleAsync(from, count, ct) overload
(default implementation ignores count). A raised stream that delivers nothing
steps back to the last good count; at the ceiling one Warning per pump.
- MTConnectDriver implements IDriverDiagnostics: sampleCount, sampleLag,
sampleSaturatedChunks, sampleCountRaises on the /hosts bag. The cap is
documented on SampleCount.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
- T-4: every ReadAsync batch fetched and parsed the whole device /current and
built a fresh index even while the /sample pump held a live one. A read is now
answered from the pump's index (read only - the pump stays its single writer)
while the current-generation pump is running, has delivered since it started and
is not degraded; /current stays the fallback, and its per-batch index is built
over a tag map frozen once per binding instead of per call. A served read clears
the read-path degradation a failed /current left.
- T-2: the /current fallback checks the answer's instanceId; a change (an Agent
restart seen by a browse-only driver) drops the cached /probe model and raises
rediscovery once per distinct id, only while the read's session is still installed.
- The pump also acts on no verdict (Degrade / latch) once its session generation
is gone, so an abandoned pump cannot write health over the new session (T-1 follow-through).
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
A pump the lifecycle retired or abandoned that finished after the restart
installed the new session published its stale cursor onto it (PublishAgentCursor
only checked for a null or identical session), so the next pump read its first
chunk as an Agent restart: index cleared, a Bad flicker on every subscribed tag,
a needless re-baseline. The pump now carries the session generation it was
started against; the cursor publish is checked under _subscriptionLock (where the
session install and generation bump are atomic) and a superseded pump also stops
folding late chunks / re-baselines into the new session's index.
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
The driver cleared its whole "last told" record whenever the subscribed alarm
set changed, assuming the rebuild that accompanies an alarm-bearing delta had
reset every condition node. The server now carries each surviving native
condition's state (acknowledgement included) across the rebuild, so re-raising a
survivor would un-acknowledge it. Only entries that left the set are dropped; a
condition that comes back later is told again onto its fresh node.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
MTConnectConditionAlarmWireTests drives a scripted Agent's Fault/Normal through the real
driver, NativeAlarmProjector and sink to a client event subscription on the raw device
folder. docs/drivers/MTConnect.md replaces 'CONDITION v1: plain String' with the alarm
mapping, opt-in authoring, multi-condition, ack, replay and comms-loss behaviour, and a
live-check recipe; EVENT vocabularies as enumerations marked won't-fix. AlarmTracking.md
lists the MTConnect source and the two new AlarmEventArgs fields.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
IWritable shipped behind write.enabled and docs/drivers/MTConnect.md told the operator to
set it, but MTConnectDriverForm — the only editor DriverFormMaps maps for this type, with
no raw-JSON escape hatch and no driver-instance API — exposed no write section, so the
documented enablement path was a hand edit of DriverInstance.DriverConfig in the config DB.
- Write-back section: switch + form text stating it is observation injection, that the
Agent's AllowPut is an independent second gate, and that it does not by itself make a
node writable over OPC UA (Tag.AccessLevel still composes CurrentWrite).
- Write added to the mirrored MTConnectConfigDto and to the form model, written in BOTH
states — an omitted block would leave a previously-authored true standing, so the switch
could never turn writing off again.
- The false 'MTConnect is read-only' header comment is gone; the doc names the new section.
No bUnit here, so the model/serialization seam is unit-tested both sides: the AdminUI test
pins the emitted bytes, and MTConnectFactoryTests parses that same document and asserts
MTConnectDriverOptions.Write.Enabled. Live page verification remains a rig step.
The comments and docs that described Driver.MTConnect-003 as live at HEAD would
have been wrong the moment 64be41d8 landed:
- code-reviews/Driver.MTConnect/findings.md — Driver.MTConnect-003 Resolved,
with the fixing commit; module open-finding count 5 -> 4.
- code-reviews/Driver.MTConnect.Contracts/findings.md — the one clause inside
Contracts-001's prose that asserted 003 was Open.
- docs/drivers/MTConnect.md — the coercion-precedence warning now states that a
browse-committed tag resolves at step 1 CARRYING the step-3 answer, and that
step 3 remains the rescue for a hand-authored / CSV / API blob with no type.
- MTConnectDriver.BuildBinding, MTConnectDataTypeInference and
MTConnectDriverOptions.RawTags remarks — same correction, each keeping a short
historical note of what the defect was so a reader meeting the old blobs still
understands them.
Comment-only in src; the driver suite (538) and AdminUI suite (1474) re-run green.
Driver.MTConnect-001 (Medium): StreamVerdict.Reopen reset the reconnect ladder
unconditionally. The InvalidDataException catch that routes an Agent OUT_OF_RANGE
to a /current re-baseline also catches an unparseable chunk and an over-sized
multipart part - neither of which a re-baseline can resolve - so the pump reopened
and failed with no delay at any point: two HTTP requests and one Warning per
iteration, forever. The Reopen arm now uses the same discriminator the transient
arm does (did THIS connection deliver a chunk?), so a buffer roll behind a working
stream still reopens instantly while a re-baseline that resolved nothing advances
BackoffFor.
Driver.MTConnect-002 (Medium): MTConnectDriverProbe requested {AgentUri}/probe
while MTConnectAgentClient requests {AgentUri}/{DeviceName}/probe, so a mistyped or
since-renamed deviceName showed GREEN on Test Connect and then Faulted the driver
at InitializeAsync (an unknown device path answers MTConnectError under HTTP 200).
The probe's minimal DTO now reads deviceName - the rule is 'which keys compose the
URL', not 'which keys are cheap to read'.
Driver.MTConnect-008 (Low): corrected two stale claims that a since-changed
RawBrowseCommitMapper invalidated (see Driver.MTConnect-003, which remains open and
belongs in AdminUI), and made DiscoverAsync log the options snapshot it
deliberately read once instead of the field.
Tests: 538 pass (534 base + 4 new, each red before its fix); AdminUI.Tests 1466 pass.
#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.
- docs/drivers/MTConnect.md: getting-started guide for the P1 Agent MVP —
config keys read off MTConnectDriverOptions/ConfigDto, capability surface,
RawPath->dataItemId coercion precedence, UNAVAILABLE->BadNoCommunication +
the rest of the quality-code table, CONDITION-as-String, browse-via-the-
universal-browser, the fixture recipe (links the existing IntegrationTests
Docker README instead of duplicating it), and a Known limitations section
covering the two pre-existing fleet-wide gaps this build surfaced
(IRediscoverable/IHostConnectivityProbe have no server consumer; no driver
form blocks Save on validation). Records write-back (MTConnect Interfaces),
P1.5 (native alarms, TIME_SERIES arrays, EVENT->enum), and P2 (SHDR ingest)
as deferred per design doc SS3.6/SS9. Documents where the build diverged
from the design: TrakHound MTConnect.NET was dropped entirely (no XML
formatter in the pinned packages, no injectable HTTP handler) in favor of
a hand-rolled System.Xml.Linq client, namespace-agnostic on LocalName.
- docs/drivers/README.md: adds MTConnect to the ground-truth driver table,
the per-driver doc list, and the fixture coverage-map list.
- docs/plans/2026-07-24-driver-expansion-tracking.md: marks the MTConnect
Wave-2 row Done (22/23 tasks; Task 21 live gate tracked separately in the
plan file, not touched here), corrects mtconnect/cppagent -> mtconnect/agent
in the fixture note, and links the new driver guide.
Deferred-cleanup decision (Task 1 review follow-up): removed
GenerateDocumentationFile/NoWarn CS1591 from Driver.MTConnect.Contracts's
csproj to match all eight sibling .Contracts projects, none of which carry
it. Verified both the Contracts project alone and the full solution still
build clean (0 warnings, 0 errors) with the flags gone — the existing XML
doc comments don't depend on GenerateDocumentationFile to compile.
Joseph Doherty