Corrects two claims made while writing the Phase 2 gate record. The docker-dev rig is NOT misconfigured: central-1/central-2 carry admin,driver deliberately — the compose says so — because they are themselves a pair that runs the MAIN cluster's drivers. And a redundant pair is not a missing concept. The application Cluster (ClusterId) already is one: it owns drivers, devices and ClusterNode rows, and Phase 1's deployment-artifact cache is keyed by it precisely so a pair shares one entry. So the root cause is wider than the alarm drain. RedundancyStateActor elects one Primary per AKKA cluster while every real unit of redundancy is an APPLICATION cluster, and ServiceLevel, the alerts emit gate and the inbound device-write gate all inherit that mis-scoping. On a fleet of pairs in one Akka cluster, exactly one driver node cluster-wide services Primary-gated work. Recommendation revised in the gate doc: fix the election scope (its own change, its own gate, because it touches the safety-critical write gate), and explicitly do NOT derive pair identity from LocalDb:Replication:PeerAddress — that would add a second parallel notion of 'my partner' that the real fix obsoletes, and the library has no initiator flag, so both halves would have to dial just to obtain a config value. Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
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, and OPC UA Client (gateway).
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
|
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 | 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.