Migration closes the FOCAS Tier-C architecture. OtOpcUa previously had
`Driver.FOCAS.Host` (NSSM-wrapped Windows service loading Fwlib64.dll via
P/Invoke) + `Driver.FOCAS.Shared` (MessagePack IPC contracts) + a C shim
DLL stand-in for unit tests. All of it is deleted; the driver is now a
single in-process managed assembly talking the FOCAS/2 Ethernet binary
protocol directly on TCP:8193.
Architecture
- Pure-managed `FocasWireClient` inlined at `src/.../Driver.FOCAS/Wire/`
(owner-imported — see Wire/FocasWireClient.cs for the full surface).
Opens two TCP sockets, runs the initiate handshake, serialises requests
on socket 2 through a semaphore, closes cleanly with PDU + socket
teardown. Both sync `IDisposable` and async `IAsyncDisposable`.
- `WireFocasClient` (same folder) adapts the wire client to OtOpcUa's
`IFocasClient` surface — fixed-tree reads, PARAM/MACRO/PMC addresses,
alarms. Writes return `BadNotWritable` by design — OtOpcUa is read-only
against FOCAS.
- `FocasDriverFactoryExtensions` now accepts `"Backend": "wire"` (default)
and `"Backend": "unimplemented"`. Legacy `ipc` and `fwlib` backends are
rejected at startup with a diagnostic pointing at the migration doc.
Deletions
- `src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Host/` — whole project + Ipc/,
Backend/, Stability/, Program.cs.
- `src/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.Shared/` — Contracts/, FrameReader,
FrameWriter, whole project.
- `tests/...Driver.FOCAS.Host.Tests/` + `.Shared.Tests/` — whole projects.
- `src/.../Driver.FOCAS/FwlibNative.cs` + `FwlibFocasClient.cs` — 21
P/Invokes + 7 `Pack=1` marshalling structs + the Fwlib-backed
`IFocasClient` implementation.
- `src/.../Driver.FOCAS/Ipc/` + `Supervisor/` — IPC client wrapper +
Host-process supervisor (backoff, circuit breaker, heartbeat, post-
mortem reader, process launcher).
- `scripts/install/Install-FocasHost.ps1` — NSSM service installer.
- `tests/.../Driver.FOCAS.Tests/{IpcFocasClientTests, IpcLoopback,
FwlibNativeHelperTests, PostMortemReaderCompatibilityTests,
SupervisorTests, FocasDriverFactoryExtensionsTests}.cs` — tests that
exercised the retired surfaces.
- `tests/.../Driver.FOCAS.IntegrationTests/Shim/` — the zig-built C shim
DLL that masqueraded as Fwlib64.dll.
Solution changes
- `ZB.MOM.WW.OtOpcUa.slnx` drops the 4 retired project refs.
- `src/.../Driver.FOCAS.csproj` drops the Shared ProjectReference, adds
`Microsoft.Extensions.Logging.Abstractions` for the optional `ILogger`
hook in `FocasWireClient`.
- `src/.../Driver.FOCAS.Cli.csproj` drops the six `<Content Include>`
entries that copied `vendor/fanuc/*.dll` into the CLI bin. CLI now uses
`WireFocasClient` directly.
- `FocasDriver` default factory flips to `Wire.WireFocasClientFactory`.
Integration tests
- New `tests/.../Driver.FOCAS.IntegrationTests/` project covering fixed-
tree reads (identity, axes, dynamic, program, operation mode, timers,
spindle load + max RPM, servo meters), user-authored PARAM / MACRO /
PMC reads, `DiscoverAsync` emission, `SubscribeAsync` + `OnDataChange`,
`IAlarmSource` raise/clear transitions, and `ProbeAsync` /
`OnHostStatusChanged`. 9 e2e tests against the focas-mock fixture
(Docker container with the vendored Python mock's native FOCAS/2
Ethernet responder).
- `scripts/integration/run-focas.ps1` orchestrates compose up → tests →
compose down. Dropped the shim-build stage + DLL-copy step + the split
testhost workaround (the latter only existed because of native-DLL
lifecycle bugs the shim tripped).
- Docker compose collapses from 11 per-series services to one `focas-sim`
service. Tests seed per-series state via `mock_load_profile` at test
start.
- Vendored focas-mock snapshot refreshed to pick up upstream's native
FOCAS/2 Ethernet responder (was 660 lines, now 1018) — the
pre-refresh snapshot only spoke the JSON admin protocol.
Tests
- 145/145 unit tests in `Driver.FOCAS.Tests` pass (was 208 pre-deletion;
63 removed tests exercised the retired IPC/shim/supervisor/Fwlib
surfaces).
- 9/9 integration tests pass against the refreshed mock.
- `FocasScaffoldingTests.Unimplemented_factory_throws_on_Create…` updated
to assert the new diagnostic message pointing at
`docs/drivers/FOCAS.md` rather than the now-gone `Fwlib64.dll`.
Docs
- `docs/drivers/FOCAS.md` rewritten for the managed wire topology —
deployment collapses to one `"Backend": "wire"` config block, no
separate service, no DLL deployment, no pipe ACL.
- `docs/drivers/FOCAS-Test-Fixture.md` updated — single TCP probe skip
gate instead of TCP + shim probe; fewer moving parts.
- `docs/drivers/README.md` row for FOCAS reflects the Tier-A managed
topology (previously listed Tier-C + `Fwlib64.dll` P/Invoke).
- `docs/Driver.FOCAS.Cli.md` drops the Tier-C architecture-note section.
- `docs/v2/implementation/focas-isolation-plan.md` marked historical —
the plan it documents was executed then superseded by the wire client.
- `docs/v2/v2-release-readiness.md` re-audited 2026-04-24. Phase 5
driver complement closed. FOCAS change-log entry added.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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, x64). Hosts every driver except Galaxy in-process; talks to Galaxy via a named pipe because MXAccess COM is 32-bit-only.
- Admin is the Blazor Server operator UI (net10, x64). Owns the Config DB draft/publish flow, ACL + role-grant authoring, fleet status +
/metricsscrape endpoint. - Galaxy.Host is a .NET Framework 4.8 x86 Windows service that wraps MXAccess COM on an STA thread for the Galaxy driver.
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 |
| Subscriptions.md | Monitored items → ISubscribable + per-driver subscription refcount |
| AlarmTracking.md | IAlarmSource + AlarmSurfaceInvoker + OPC UA alarm conditions |
| DataTypeMapping.md | Per-driver DriverAttributeInfo → OPC UA variable types |
| IncrementalSync.md | Address-space rebuild on redeploy + sp_ComputeGenerationDiff |
| HistoricalDataAccess.md | IHistoryProvider as a per-driver optional capability |
| 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 |
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 — MXAccess bridge, Host/Proxy split, named-pipe IPC |
| drivers/Galaxy-Repository.md | Galaxy-specific discovery via the ZB SQL database |
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 |
| security.md | Transport security profiles, LDAP auth, ACL trie, role grants, OTOPCUA0001 analyzer |
| Redundancy.md | RedundancyCoordinator, ServiceLevelCalculator, apply-lease, Prometheus metrics |
| ServiceHosting.md | Three-process deploy (Server + Admin + Galaxy.Host) install/uninstall |
| 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 |
| reqs/ServiceHostReqs.md | Per-process hosting reqs |
| reqs/ClientRequirements.md | Client CLI + UI reqs |
| reqs/GalaxyRepositoryReqs.md | Galaxy-scoped repository reqs |
| reqs/MxAccessClientReqs.md | Galaxy-scoped MXAccess reqs |
| 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/implementation/phase--.md — per-phase execution plans with exit-gate evidence