Joseph Doherty
2d20aeb779
#519 — a driver's OPC UA status code now reaches a client with its sub-code intact. DriverInstanceActor projected the driver's uint onto a 3-state Good/Uncertain/Bad enum and OtOpcUaNodeManager re-expanded Bad to a bare 0x80000000, so BadNoCommunication, BadTypeMismatch and BadNotSupported were indistinguishable on the wire and every driver's status constants (incl. the 16 #497 had just corrected) were diagnostic in logs only. Resolved by option (b): the raw uint rides AttributeValuePublished -> AttributeValueUpdate -> IOpcUaAddressSpaceSink.WriteValue, OpcUaQuality is deleted, and severity classification is a helper (OpcUaStatus.IsGood/IsUncertain/IsBad). The surface was wider than the issue costed (41 files, not "the sink and 3 implementations"): OpcUaQuality had non-driver producers with no uint to carry. Each got its natural code — BadInternalError for a failed virtual-tag script, BadNoCommunication for driver comms loss — and ScriptedAlarmHostActor's pair of mutually-inverse uint<->enum mappers is deleted, having round-tripped a code the engine already held. AddressSpaceApplier's removal writes deliberately keep the generic Bad: not losing a code the driver had is this issue; inventing one for the deploy path is a separate call. Behaviour change: WriteAlarmQuality fires its Part 9 event on a status-code change rather than a severity-bucket change. While the annotation was 3-state those were the same predicate; now a move between two Bad reasons changes what a subscriber reads. New SDK-free named constants live on Commons.OpcUa.OpcUaStatus, and StatusCodeParityTests is widened to cover them — that guard is reflection-driven, so it can only see a named constant, never an inline literal. #517 — the symptom is real but the issue named the wrong path and its fix was unsafe. ShutdownAsync cannot race: DriverInstanceActor calls it from PostStop, after the mailbox drains. (Core/Hosting/DriverHost, the one class with a concurrent GetHealth, has no production call site.) InitializeAsync can: it runs on a fire-and-forget Task.Run, and MTConnectDriver writes Healthy then starts loops that can throw into a catch which disposes the client before writing Faulted. Moving the write earlier, as suggested, inverts the terminal state — teardown drains in-flight loops that write health as they unwind, so a late loop could leave Healthy at rest with every connection closed. The fix is a bracket (conservative before, terminal after), applied to MTConnect's init-failure path only; shutdown keeps its single trailing write, and the rule plus the reachability table are documented on IDriver.ShutdownAsync. CalculationDriver.GetHealth returned a hard-coded Healthy that consulted nothing — Healthy before initialize, after shutdown and after dispose. Now derived from _running. Its test, named Health_is_always_Connected, asserted the defect and is replaced. Every new guard was falsified by breaking the production code and watching it go red. The two sub-code tests each assert two different Bad codes, since a single-code assertion could pass against a hard-coded constant under the old projection. Pre-existing failures, verified unchanged on a stashed tree and not chased: 4 in Driver.AbLegacy.IntegrationTests (slc500/micrologix/plc5 fixtures not up) and 3 in Host.IntegrationTests. Closes #517 Closes #519 Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo
OtOpcUa
OPC UA server (.NET 10 AnyCPU) that exposes a fleet of industrial drivers as a single OPC UA address space. Drivers ship in-process for AVEVA System Platform Galaxy (via the sibling mxaccessgw repo), Modbus TCP, Siemens S7, Allen-Bradley CIP (ControlLogix / CompactLogix), Allen-Bradley Legacy (SLC 500 / MicroLogix), Beckhoff TwinCAT (ADS), FANUC FOCAS, OPC UA Client (gateway), and MQTT (broker subscribe; Sparkplug B in progress).
A cross-platform client stack (.NET 10) — shared library, CLI, and Avalonia desktop app — connects to any OPC UA server.
Architecture
OPC UA Clients (CLI, Desktop UI, 3rd-party)
|
v
+-------------------------------------+
| OtOpcUa.Server (.NET 10 AnyCPU) |
| address space + capability fan-out|
+-------------------------------------+
| | | | | | | |
Galaxy Modbus S7 AbCip AbLeg TwinCAT FOCAS OpcUaClient MQTT
|
v
mxaccessgw (sibling repo, gRPC)
|
v
MXAccess COM (x86 worker, on AVEVA box)
Galaxy is the only driver with an external runtime: it speaks gRPC to a separately installed mxaccessgw server (sibling repo at c:\Users\dohertj2\Desktop\mxaccessgw\) which owns the MXAccess COM apartment and the x86/STA bitness constraint server-side. Everything in this repo is platform-agnostic .NET 10.
Prerequisites
- .NET 10 SDK (server, drivers, clients all target .NET 10)
- SQL Server reachable for the central config DB
- For Galaxy specifically: a running
mxaccessgwdeployment — see docs/v2/Galaxy.ParityRig.md - For historian read-back / alarm history / continuous historization: a running
ZB.MOM.WW.HistorianGatewaydeployment (the sole historian backend; consumed as theZB.MOM.WW.HistorianGateway.ClientgRPC package). It must runRuntimeDb:Enabled=true+RuntimeDb:EventReadsEnabled=true, and the API key must carryhistorian:read+historian:write+historian:tags:writescopes.
Quick Start
dotnet restore ZB.MOM.WW.OtOpcUa.slnx
dotnet build ZB.MOM.WW.OtOpcUa.slnx
dotnet test ZB.MOM.WW.OtOpcUa.slnx
# Run the server in dev (foreground)
dotnet run --project src/Server/ZB.MOM.WW.OtOpcUa.Host
The server starts on opc.tcp://localhost:4840 with the None security profile. Configure Security.Profiles in src/Server/ZB.MOM.WW.OtOpcUa.Host/appsettings.json to enable Basic256Sha256-Sign or Basic256Sha256-SignAndEncrypt. See docs/security.md.
Install as Windows Services
Production deployment is driven by scripts/install/Install-Services.ps1, which registers the OtOpcUa server service under a chosen service account. Historian support requires a separately deployed ZB.MOM.WW.HistorianGateway and Galaxy support a separately installed mxaccessgw — neither this repo nor the install script provisions them.
.\scripts\install\Install-Services.ps1 `
-InstallRoot 'C:\Program Files\OtOpcUa' `
-ServiceAccount 'DOMAIN\svc-otopcua'
The historian backend is the external ZB.MOM.WW.HistorianGateway (not installed by this script). See the script header and docs/ServiceHosting.md for full options.
Client CLI
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- connect -u opc.tcp://localhost:4840
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- browse -u opc.tcp://localhost:4840 -r -d 3
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- read -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode"
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- write -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -v 42
dotnet run --project src/Client/ZB.MOM.WW.OtOpcUa.Client.CLI -- subscribe -u opc.tcp://localhost:4840 -n "ns=2;s=SomeNode" -i 500
See docs/Client.CLI.md and docs/Client.UI.md.
Documentation
Architecture deep-dives
| Topic | Doc |
|---|---|
| OPC UA server composition, namespace fan-out, Polly invoker | docs/OpcUaServer.md |
| Address space layout | docs/AddressSpace.md |
| Read / Write dispatch (driver vs virtual vs scripted-alarm) | docs/ReadWriteOperations.md |
| Incremental sync (driver-backend rediscovery + config publishes) | docs/IncrementalSync.md |
| Service hosting (Server + Admin; external HistorianGateway backend) | docs/ServiceHosting.md |
| Security (transport, LDAP, certificates) | docs/security.md |
| Redundancy | docs/Redundancy.md |
| Status dashboard | docs/StatusDashboard.md |
Drivers
| Topic | Doc |
|---|---|
| Driver specs (per-driver capability surface, config, addressing) | docs/v2/driver-specs.md |
| Galaxy driver | docs/drivers/Galaxy.md |
| Modbus / S7 / AbCip / AbLegacy / TwinCAT / FOCAS / OpcUaClient / MQTT | docs/drivers/ |
| Galaxy parity rig (mxaccessgw setup) | docs/v2/Galaxy.ParityRig.md |
| Galaxy performance + tracing | docs/v2/Galaxy.Performance.md |
Clients
| Topic | Doc |
|---|---|
| Client CLI | docs/Client.CLI.md |
| Client UI (Avalonia desktop) | docs/Client.UI.md |
v1 archive
The original v1 in-process MXAccess docs (Galaxy.Host topology, Configuration env vars, AlarmTracking, DataTypeMapping, HistoricalDataAccess, Subscriptions, etc.) are preserved under docs/v1/ — historical reference only. PR 7.2 retired the v1 architecture on 2026-04-30; current state is documented in the sections above.
License
Internal use only.