Files
lmxopcua/docs
Joseph Doherty ee39c169df
v2-ci / unit-tests (push) Has been cancelled
fix(historian): refuse aggregates not valid for the node's DataType up front (#897)
TimeAverage / Total on a Boolean node over the Gateway backend (AVEVA discrete tag, live
SysPulse) went to the gateway since native TimeAverage/Total became default-on (#694). AVEVA
refuses both modes at StartQuery; the gateway reports that only as Internal /
HistorianServerOperationException (the same answer as a historian storage fault), so the
node answered BadHistoryOperationUnsupported and the read counted as a backend failure.

HistoryRead-Processed now checks the node's scalar DataType before calling any backend and
answers BadAggregateNotSupported (Part 11 6.5.4: "If the Aggregate is not valid for the Node
then the StatusCode shall be Bad_AggregateNotSupported"). Nothing is sent, nothing is counted.
- Shared, every backend: HistoryAggregateDataTypes (Core.Abstractions) applies Part 13
  5.4.2.3 Table 50: the numeric-only aggregates (Average, TimeAverage(2), Total(2), Min/Max,
  ActualTime, Range, Delta, DeltaBounds, Interpolative, stddev/variance) on a String or
  DateTime node are refused. Client-visible: the SQL backends used to answer every interval
  BadAggregateInvalidInputs.
- Per backend: IHistorianDataSource.SupportsAggregateFor(aggregate, TypeCode?) (default true;
  every production backend declares it, guard-tested). Gateway: false for native
  TimeAverage/Total on a Boolean node. SqlServer/QuestDb: true, since they serve Boolean as
  0/1 (stepped), so Boolean stays served there, as do the Gateway's raw-evaluated aggregates.

The residual case (a node declared numeric whose AVEVA tag is discrete) cannot be told apart
from a historian fault on the wire and still counts; that needs the gateway to surface
AVEVA's native error code as a deterministic status.

Tests: HistoryAggregateDataTypesTests, guard test, node-manager String/DateTime and per-type
refusals, Gateway capability matrix, DiscreteTagTimeWeightedWireTests (production Gateway
backend over an AVEVA-shaped fake: unsent, 0 health failures, positive controls). Each
mutation (no check, no shared rule, no backend hint, Gateway hint true, shared rule always
true, SQL inheriting the default) fails at least one. Live gate re-run read-only against
AVEVA 2023 R2 via a private HistorianGateway fa9cf31 container: SysPulse TimeAverage on the
wire = BadAggregateNotSupported, health failures unchanged; #801 gate 244 cases pass.

Claude-Session: https://claude.ai/code/session_01GT67ACmpMR7b9LGRPLijMi
2026-11-13 00:41:33 -05:00
..
…

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.Admin services fused into a single role-gated OtOpcUa.Host binary, 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, 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_ROLES env 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, 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 Historical v1 design: history as a per-driver capability (retired; history is now server-side, see Historian.md)
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 RedundancyStateActor (cluster-scoped singleton), ServiceLevelCalculator, IRedundancyRoleView, per-cluster meshes, 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:

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.