Files
lmxopcua/docs/README.md
Joseph Doherty 33054c3275 docs: drop dangling FOCAS refs + link unreferenced v2 design docs
- docs/drivers/FOCAS.md and docs/v2/implementation/focas-wire-protocol.md
  pointed at focas-deployment.md and focas-simulator-plan.md, both of
  which were untracked drafts that have since been removed. Drop the
  refs (the wire-protocol companion now stands on its own; deployment
  guidance lives inline in the FOCAS driver doc).
- Link the orphan v2 design docs from docs/README.md (multi-host
  dispatch, v2 release readiness, the historical lmx-followups tracker)
  and from modbus-test-plan.md (s7.md, mitsubishi.md per-family quirk
  catalogs, sibling to dl205.md).

Surfaced by the doc audit; no content changes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-30 09:42:28 -04:00

7.9 KiB

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

  • Core owns the OPC UA stack, address space, session/security/subscription machinery.
  • 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.
  • Server is the OPC UA endpoint process (net10, AnyCPU). Hosts every driver in-process. The Galaxy driver reaches MXAccess via gRPC to a separately-installed mxaccessgw sidecar (sibling repo); it is no longer hosted from this repo.
  • Admin is the Blazor Server operator UI (net10, x64). Owns the Config DB draft/publish flow, ACL + role-grant authoring, fleet status + /metrics scrape endpoint.

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 → CapabilityInvokerIReadable/IWritable
Subscriptions.md Monitored items → ISubscribable + per-driver subscription refcount (v1 archive)
AlarmTracking.md IAlarmSource + AlarmSurfaceInvoker + OPC UA alarm conditions (v1 archive)
DataTypeMapping.md Per-driver DriverAttributeInfo → OPC UA variable types (v1 archive — live mapping is in src/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
ScriptedAlarms.md Core.ScriptedAlarms — script-predicate IAlarmSource + Part 9 state machine

Two Core subsystems are shipped without a dedicated top-level doc; see the section in the linked doc:

Project See
Core.AlarmHistorian AlarmTracking.md § Alarm historian sink (v1 archive)
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 appsettings bootstrap + Config DB + Admin UI draft/publish (v1 archive — OTOPCUA_GALAXY_* env vars now live in mxaccessgw config)
security.md Transport security profiles, LDAP auth, ACL trie, role grants, OTOPCUA0001 analyzer
Redundancy.md RedundancyCoordinator, ServiceLevelCalculator, apply-lease, Prometheus metrics
ServiceHosting.md Two-process deploy (Server + Admin) install/uninstall, plus the optional OtOpcUaWonderwareHistorian sidecar
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.