d11dd0520b
Three root-cause fixes to get an elevated dev-box shell past session open through to real MXAccess reads: 1. PipeAcl — drop BUILTIN\Administrators deny ACE. UAC's filtered token carries the Admins SID as deny-only, so the deny fired even from non-elevated admin-account shells. The per-connection SID check in PipeServer.VerifyCaller remains the real authorization boundary. 2. PipeServer — swap the Hello-read / VerifyCaller order. ImpersonateNamedPipeClient returns ERROR_CANNOT_IMPERSONATE until at least one frame has been read from the pipe; reading Hello first satisfies that rule. Previously the ACL deny-first path masked this race — removing the deny ACE exposed it. 3. GalaxyIpcClient — add a background reader + single pending-response slot. A RuntimeStatusChange event between OpenSessionRequest and OpenSessionResponse used to satisfy the caller's single ReadFrameAsync and fail CallAsync with "Expected OpenSessionResponse, got RuntimeStatusChange". The reader now routes response kinds (and ErrorResponse) to the pending TCS and everything else to a handler the driver registers in InitializeAsync. The Proxy was already set up to raise managed events from RaiseDataChange / RaiseAlarmEvent / OnHostConnectivityUpdate — those helpers had no caller until now. 4. RedundancyPublisherHostedService — swallow BadServerHalted while polling host.Server.CurrentInstance. StandardServer throws that code during startup rather than returning null, so the first poll attempt crashed the BackgroundService (and the host) before OnServerStarted ran. This race was latent behind the Galaxy init failure above. Updates docs that described the Admins deny ACE + mandatory non-elevated shells, and drops the admin-skip guards from every Galaxy integration + E2E fixture that had them (IpcHandshakeIntegrationTests, EndToEndIpcTests, ParityFixture, LiveStackFixture, HostSubprocessParityTests). Adds GalaxyIpcClientRoutingTests covering the router's request/response match, ErrorResponse, event-between-call, idle event, and peer-close paths. Verified live on the dev box against the p7-smoke cluster (gen 6): driver registered=1 failedInit=0, Phase 7 bridge subscribed, OPC UA server up on 4840, MXAccess read round-trip returns real data with Status=0x00000000. Task #112 — partial: Galaxy live stack is functional end-to-end. The supplied test-galaxy.ps1 script still fails because the UNS walker encodes TagConfig JSON as the tag's NodeId instead of the seeded TagId (pre-existing; separate issue from this commit). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Drivers
OtOpcUa is a multi-driver OPC UA server. The Core (ZB.MOM.WW.OtOpcUa.Core + Core.Abstractions + Server) owns the OPC UA stack, address space, session/security/subscription machinery, resilience pipeline, and namespace kinds (Equipment + SystemPlatform). Drivers plug in through capability interfaces defined in src/ZB.MOM.WW.OtOpcUa.Core.Abstractions/:
IDriver— lifecycle (InitializeAsync,ReinitializeAsync,ShutdownAsync,GetHealth)IReadable/IWritable— one-shot reads and writesITagDiscovery— address-space enumerationISubscribable— driver-pushed data-change streamsIHostConnectivityProbe— per-host reachability eventsIPerCallHostResolver— multi-host drivers that route each call to a target endpoint at dispatch timeIAlarmSource— driver-emitted OPC UA A&C eventsIHistoryProvider— raw / processed / at-time / events HistoryRead (see HistoricalDataAccess.md)IRediscoverable— driver-initiated address-space rebuild notifications
Each driver opts into only the capabilities it supports. Every async capability call at the Server dispatch layer goes through CapabilityInvoker (Core/Resilience/CapabilityInvoker.cs), which wraps it in a Polly pipeline keyed on (DriverInstanceId, HostName, DriverCapability). The OTOPCUA0001 analyzer enforces the wrap at build time. Drivers themselves never depend on Polly; they just implement the capability interface and let the Core wrap it.
Driver type metadata is registered at startup in DriverTypeRegistry (src/ZB.MOM.WW.OtOpcUa.Core.Abstractions/DriverTypeRegistry.cs). The registry records each type's allowed namespace kinds (Equipment / SystemPlatform / Simulated), its JSON Schema for DriverConfig / DeviceConfig / TagConfig columns, and its stability tier per docs/v2/driver-stability.md.
Ground-truth driver list
| Driver | Project path | Tier | Wire / library | Capabilities | Notable quirk |
|---|---|---|---|---|---|
| Galaxy | Driver.Galaxy.{Shared, Host, Proxy} |
C | MXAccess COM + aahClientManaged + SqlClient |
IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IAlarmSource, IHistoryProvider, IRediscoverable, IHostConnectivityProbe | Out-of-process — Host is its own Windows service (.NET 4.8 x86 for the COM bitness constraint); Proxy talks to Host over a named pipe |
| Modbus TCP | Driver.Modbus |
A | NModbus-derived in-house client | IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IHostConnectivityProbe | Polled subscriptions via the shared PollGroupEngine. DL205 PLCs are covered by AddressFormat=DL205 (octal V/X/Y/C/T/CT translation) — no separate driver |
| Siemens S7 | Driver.S7 |
A | S7netplus | IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IHostConnectivityProbe | Single S7netplus Plc instance per PLC serialized with SemaphoreSlim — the S7 CPU's comm mailbox is scanned at most once per cycle, so parallel reads don't help |
| AB CIP | Driver.AbCip |
A | libplctag CIP | IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IHostConnectivityProbe, IPerCallHostResolver, IAlarmSource | ControlLogix / CompactLogix. Tag discovery uses the @tags walker to enumerate controller-scoped + program-scoped symbols; UDT member resolution via the UDT template reader |
| AB Legacy | Driver.AbLegacy |
A | libplctag PCCC | IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IHostConnectivityProbe, IPerCallHostResolver | SLC 500 / MicroLogix. File-based addressing (N7:0, F8:0) — no symbol table, tag list is user-authored in the config DB |
| TwinCAT | Driver.TwinCAT |
B | Beckhoff TwinCAT.Ads (TcAdsClient) |
IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IHostConnectivityProbe, IPerCallHostResolver | The only native-notification driver outside Galaxy — ADS delivers ValueChangedCallback events the driver forwards straight to ISubscribable.OnDataChange without polling. Symbol tree uploaded via SymbolLoaderFactory |
| FOCAS | Driver.FOCAS |
A | Pure-managed FocasWireClient — FOCAS/2 Ethernet binary protocol on TCP:8193, inlined into the driver assembly |
IDriver, ITagDiscovery, IReadable, ISubscribable, IHostConnectivityProbe, IPerCallHostResolver, IAlarmSource | Read-only by design (WriteAsync returns BadNotWritable). CNC-shaped data model (axes, spindle, PMC, macros, alarms) not a flat tag map. Previously Tier-C (Host + P/Invoke + shim DLL); retired in the 2026-04-24 migration when the managed wire client landed |
| OPC UA Client | Driver.OpcUaClient |
B | OPCFoundation Opc.Ua.Client |
IDriver, ITagDiscovery, IReadable, IWritable, ISubscribable, IAlarmSource, IHistoryProvider, IHostConnectivityProbe | Gateway/aggregation driver. Opens a single Session against a remote OPC UA server and re-exposes its address space. Owns its own ApplicationConfiguration (distinct from Client.Shared) because it's always-on with keep-alive + TransferSubscriptions across SDK reconnect, not an interactive CLI |
Per-driver documentation
-
Galaxy has its own docs in this folder because the out-of-process architecture + MXAccess COM rules + Galaxy Repository SQL + Historian + runtime probe manager don't fit a single table row:
- Galaxy.md — COM bridge, STA pump, IPC, runtime probes
- Galaxy-Repository.md — ZB SQL reader,
LocalPlatformscope filter, change detection
-
FOCAS has a short getting-started doc because the Tier-C two-project deployment + backend-selection env var + alarm projection opt-in all need explaining up front:
- FOCAS.md — deployment, config, capability surface, alarm projection, troubleshooting
-
All other drivers share a single per-driver specification in docs/v2/driver-specs.md — addressing, data-type maps, connection settings, and quirks live there. That file is the authoritative per-driver reference; this index points at it rather than duplicating.
Test-fixture coverage maps
Each driver has a dedicated fixture doc that lays out what the integration / unit harness actually covers vs. what's trusted from field deployments. Read the relevant one before claiming "green suite = production-ready" for a driver.
- AB CIP — Dockerized
ab_server(multi-stage build from libplctag source); atomic-read smoke across 4 families; UDT / ALMD / family quirks unit-only - Modbus — Dockerized
pymodbus+ per-family JSON profiles (4 compose profiles); best-covered driver, gaps are error-path-shaped - Siemens S7 — Dockerized
python-snap7server; DB/MB read + write round-trip verified end-to-end on:1102 - AB Legacy — Dockerized
ab_serverPCCC mode across SLC500 / MicroLogix / PLC-5 profiles (task #224); N/F/L-file round-trip verified end-to-end./1,0cip-path required for the Docker fixture; real hardware uses empty. Residual gap: bit-file writes (B3:0/5) still surface BadState — real HW / RSEmulate 500 for those - TwinCAT — XAR-VM integration scaffolding (task #221); three smoke tests skip when VM unreachable. Unit via
FakeTwinCATClientwith native-notification harness - FOCAS — no integration fixture, unit-only via
FakeFocasClient; Tier C out-of-process isolation scoped but not shipped - OPC UA Client — no integration fixture, unit-only via mocked
Session; loopback against this repo's own server is the obvious next step - Galaxy — richest harness: E2E Host subprocess + ZB SQL live-smoke + MXAccess opt-in
Related cross-driver docs
- HistoricalDataAccess.md —
IHistoryProviderdispatch, aggregate mapping, continuation points. The Galaxy driver's Aveva Historian implementation is the first; OPC UA Client forwards to the upstream server; other drivers do not implement the interface and returnBadHistoryOperationUnsupported. - AlarmTracking.md —
IAlarmSourceevent model and filtering. - Subscriptions.md — how the Server multiplexes subscriptions onto
ISubscribable.OnDataChange. - docs/v2/driver-stability.md — tier system (A / B / C), shared
CapabilityPolicydefaults per tier × capability,MemoryTrackinghybrid formula, and process-level recycle rules. - docs/v2/plan.md — authoritative vision, architecture decisions, migration strategy.