Every value verified against Opc.Ua.StatusCodes in the pinned SDK (1.5.378.106) by reflection, not by copying siblings. All are client-visible: OPC UA clients branch on status. The three named in #497: - Historian.Gateway SampleMapper "BadNoData" 0x800E0000 -> 0x809B0000 (0x800E0000 is BadServerHalted) - Galaxy "BadTimeout" 0x800B0000 -> 0x800A0000 (0x800B0000 is BadServiceUnsupported) - TwinCAT BadTypeMismatch 0x80730000 -> 0x80740000 (0x80730000 is BadWriteNotSupported) BadTypeMismatch was wrong in three MORE drivers the issue did not name — FOCAS, AbLegacy and AbCip carried the same 0x80730000. Every call site is a FormatException/InvalidCastException conversion failure, so the name was right and the value was wrong in all four. Adding the reflection guard then surfaced nine further defects offline tests had never checked: - Galaxy GoodLocalOverride 0x00D80000 -> 0x00960000 (not a UA code at all) - Galaxy UncertainLastUsableValue 0x40A40000 -> 0x40900000 - Galaxy UncertainSensorNotAccurate 0x408D0000 -> 0x40930000 - Galaxy UncertainEngineeringUnitsExceeded 0x408E0000 -> 0x40940000 - Galaxy UncertainSubNormal 0x408F0000 -> 0x40950000 - TwinCAT BadOutOfService 0x80BE0000 -> 0x808D0000 (was BadProtocolVersionUnsupported) - TwinCAT BadInvalidState 0x80350000 -> 0x80AF0000 (was BadAttributeIdInvalid) - AbCip/AbLegacy GoodMoreData 0x00A70000 -> 0x00A60000 (was GoodCommunicationEvent) - Historian.Gateway GatewayQualityMapper Good_LocalOverride 0x00D80000 -> 0x00960000 Galaxy's whole Uncertain block read as though the OPC DA quality byte could be shifted into the UA substatus position; it cannot — the substatuses are an unrelated enumeration. GatewayQualityMapper already held the correct table, which is what the Galaxy values are now reconciled against. Guard: StatusCodeParityTests (Core.Abstractions.Tests, which already project- references every driver) reflects over every `const uint` in the deployed ZB.MOM.WW.OtOpcUa.Driver.*.dll whose name reads as a status code, and asserts it equals Opc.Ua.StatusCodes.<name>. Discovery is by convention, so a new driver assembly referenced by that project is covered with no edit here. It went red on all nine defects above before the fixes and now checks 109 constants green. Because reflection can only see a NAMED constant, two inline literals were hoisted so the guard can reach them: Galaxy's BadTimeout/Bad into StatusCodeMap, and GatewayQualityMapper's 15-entry table into a new HistorianStatusCodes. An inline `0x800B0000u, // BadTimeout` at a call site is exactly how the Galaxy defect survived. The drivers stay SDK-free by design; only the test project references Opc.Ua.Core, as the oracle. Also corrected: tests that pinned the wrong values (Galaxy StatusCodeMapTests, SampleMapperTests, GatewayQualityMapperTests — all written from the same bad source), a mislabelled comment in DriverInstanceActorTests, and stale constants in two design docs, one of them the unexecuted MTConnect driver design that would have propagated BadNoData's wrong value into a new driver. The CLI's SnapshotFormatter value->name table was checked against the SDK and is correct; no change needed.
OtOpcUa documentation
Two tiers of documentation live here:
- Current reference at the top level (
docs/*.md) — describes what's shipped today. Start here for operator + integrator reference. - Implementation history + design notes at
docs/v2/*.md— the authoritative plan + decision log the current reference is built from. Start here when you need the why behind an architectural choice, or when a top-level doc says "see plan.md § X".
The project was originally called LmxOpcUa (a single-driver Galaxy/MXAccess OPC UA server) and has since become OtOpcUa, a multi-driver OPC UA server platform. Any lingering LmxOpcUa-string in a path you see in docs is a deliberate residual (executable name lmxopcua-cli, client PKI folder {LocalAppData}/LmxOpcUaClient/) — fixing those requires migration shims + is tracked as follow-ups.
Platform overview
v2 (2026-05-26): the separate
OtOpcUa.Server+OtOpcUa.Adminservices fused into a single role-gatedOtOpcUa.Hostbinary, joined by an Akka.NET cluster. See v2 design for the architectural decision.
- Core owns shared abstractions (driver capability contracts, scripting, virtual tags, alarm historian).
- Drivers plug in via capability interfaces in
ZB.MOM.WW.OtOpcUa.Core.Abstractions:IDriver,IReadable,IWritable,ITagDiscovery,ISubscribable,IHostConnectivityProbe,IAlarmSource,IHistoryProvider,IPerCallHostResolver. Each driver opts into whichever it supports. - Host (
src/Server/ZB.MOM.WW.OtOpcUa.Host) is the single fused binary (.NET 10, AnyCPU).OTOPCUA_ROLESenv decides what to mount:admin(Blazor + control-plane singletons),driver(OPC UA endpoint + per-node actors), or both. See ServiceHosting.md. - Cluster + ControlPlane + Runtime + AdminUI + Security sit between Core and Host. The cluster glues per-node actors into one logical fleet; the control-plane singletons (deploy coordinator, audit writer, redundancy state) live on the admin role-leader. See Redundancy.md.
- The Galaxy driver still reaches MXAccess via gRPC to a separately-installed mxaccessgw sidecar (sibling repo).
Where to find what
Architecture + data-path reference
| Doc | Covers |
|---|---|
| OpcUaServer.md | Top-level server architecture — Core, driver dispatch, Config DB, generations |
| AddressSpace.md | GenericDriverNodeManager + ITagDiscovery + IAddressSpaceBuilder |
| ReadWriteOperations.md | OPC UA Read/Write → CapabilityInvoker → IReadable/IWritable |
| DriverLifecycle.md | Server-side driver lifecycle + infrastructure contracts (IDriverFactory, IDriverProbe, IDriverSupervisor, IDriverHealthPublisher, IDriverConfigEditor, IHistorianDataSource) + the Commons library |
| Subscriptions.md | Monitored items → ISubscribable + per-driver subscription refcount (v1 archive) |
| AlarmTracking.md | IAlarmSource + AlarmSurfaceInvoker + OPC UA alarm conditions — native Galaxy alarms end-to-end (live) |
| AlarmTracking.md | Original alarm-tracking write-up (v1 archive) |
| AlarmHistorian.md | Core.AlarmHistorian store-and-forward sink — LocalDbStoreAndForwardSink, the replicated alarm_sf_events buffer + Primary-only drain, IAlarmHistorianWriter, dead-letter/retry/eviction |
| DataTypeMapping.md | Per-driver DriverAttributeInfo → OPC UA variable types (v1 archive — live mapping is in src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Browse/DataTypeMap.cs) |
| IncrementalSync.md | Address-space rebuild on redeploy + sp_ComputeGenerationDiff |
| HistoricalDataAccess.md | IHistoryProvider as a per-driver optional capability (v1 archive) |
| VirtualTags.md | Core.Scripting + Core.VirtualTags — Roslyn script sandbox, engine, dispatch alongside driver tags |
| ScriptEditor.md | Monaco script editor — Roslyn-backed IntelliSense (completions, diagnostics, hover, tag-path) for C# virtual-tag scripts; AdminUI/ScriptAnalysis/ backend |
| ScriptedAlarms.md | Core.ScriptedAlarms — script-predicate IAlarmSource + Part 9 state machine |
One Core subsystem is shipped without a dedicated top-level doc; see the section in the linked doc:
| Project | See |
|---|---|
Analyzers (Roslyn OTOPCUA0001) |
security.md § OTOPCUA0001 Analyzer |
Drivers
| Doc | Covers |
|---|---|
| drivers/README.md | Index of the eight shipped drivers + capability matrix |
| drivers/Galaxy.md | Galaxy driver — in-process gRPC client to the mxaccessgw sidecar |
| v1/drivers/Galaxy-Repository.md | Galaxy-specific discovery via the ZB SQL database (v1 archive — the gateway owns this path now) |
For Modbus / S7 / AB CIP / AB Legacy / TwinCAT / FOCAS / OPC UA Client specifics, see v2/driver-specs.md.
Operational
| Doc | Covers |
|---|---|
| Configuration.md | Live appsettings + environment-variable reference (current state) |
| Configuration.md | appsettings bootstrap + Config DB + Admin UI draft/publish (v1 archive — OTOPCUA_GALAXY_* env vars now live in mxaccessgw config) |
| Uns.md | The global /uns master tree — manage Area/Line/Equipment/Tag/VirtualTag fleet-wide; replaces the per-cluster UNS/Equipment/Tags tabs |
| security.md | Transport security profiles, LDAP auth, ACL trie, role grants, OTOPCUA0001 analyzer |
| Redundancy.md | RedundancyCoordinator, ServiceLevelCalculator, apply-lease, Prometheus metrics |
| Reservations.md | Fleet-wide ZTag / SAPID external-ID reservations — publish-time claim, release flow |
| ServiceHosting.md | Single fused OtOpcUa.Host binary install/uninstall with OTOPCUA_ROLES gating; the historian backend is the external HistorianGateway |
| StatusDashboard.md | Pointer — superseded by v2/admin-ui.md |
Client tooling
| Doc | Covers |
|---|---|
| Client.CLI.md | otopcua-cli — OPC UA command-line client |
| Client.UI.md | Avalonia desktop client |
| DriverClis.md | Driver test-client CLIs — index + shared commands |
| Driver.Modbus.Cli.md | otopcua-modbus-cli — Modbus-TCP |
| Driver.AbCip.Cli.md | otopcua-abcip-cli — ControlLogix / CompactLogix / Micro800 / GuardLogix |
| Driver.AbLegacy.Cli.md | otopcua-ablegacy-cli — SLC / MicroLogix / PLC-5 (PCCC) |
| Driver.S7.Cli.md | otopcua-s7-cli — Siemens S7-300 / S7-400 / S7-1200 / S7-1500 |
| Driver.TwinCAT.Cli.md | otopcua-twincat-cli — Beckhoff TwinCAT 2/3 ADS |
| Driver.FOCAS.Cli.md | otopcua-focas-cli — Fanuc FOCAS/2 CNC |
Requirements
| Doc | Covers |
|---|---|
| reqs/HighLevelReqs.md | HLRs — numbered system-level requirements |
| reqs/OpcUaServerReqs.md | OPC UA server-layer reqs |
| v1/reqs/ServiceHostReqs.md | Per-process hosting reqs (v1 archive — only OtOpcUa server hosting remains in scope post-PR-7.2) |
| reqs/ClientRequirements.md | Client CLI + UI reqs |
| v1/reqs/GalaxyRepositoryReqs.md | Galaxy-scoped repository reqs (v1 archive — owned by mxaccessgw today) |
| v1/reqs/MxAccessClientReqs.md | Galaxy-scoped MXAccess reqs (v1 archive — owned by mxaccessgw today) |
| reqs/StatusDashboardReqs.md | Pointer — superseded by Admin UI |
Implementation history (docs/v2/)
Design decisions + phase plans + execution notes. Load-bearing cross-references from the top-level docs:
- v2/plan.md — authoritative v2 vision doc + numbered decision log (referenced as "decision #N" elsewhere)
- v2/admin-ui.md — Admin UI spec
- v2/acl-design.md — data-plane ACL + permission-trie design (Phase 6.2)
- v2/config-db-schema.md — Config DB schema reference
- v2/driver-specs.md — per-driver addressing + quirks for every shipped protocol
- v2/dev-environment.md — dev-box bootstrap
- v2/test-data-sources.md — integration-test simulator matrix (includes the pinned libplctag
ab_serverversion for AB CIP tests) - v2/multi-host-dispatch.md — per-PLC circuit breakers (Phase 6.1 decision #144)
- v2/v2-release-readiness.md — release-readiness tracker
- v2/phase-7-status.md — Phase 7 reconciliation: what shipped vs. the plan, and the five remaining gaps
- v2/implementation/phase--.md — per-phase execution plans with exit-gate evidence
v1 archive
The v1 in-process MXAccess architecture (Galaxy.Host + Galaxy.Proxy + Galaxy.Shared, .NET 4.8 x86 COM, the OtOpcUaGalaxyHost Windows service) was retired in PR 7.2 (2026-04-30, commit ae7106d). Docs that described that shape are kept under v1/ as historical record — see v1/README.md for the index.