Joseph Doherty
b4480bf45a
The fixture Agent flips to AllowPut = true (its comment rewritten: writes are in
scope now that the driver implements IWritable) and the suite grows three
env-gated write legs, all still Assert.Skip-clean with no Agent reachable.
Devices.xml gains a DataItem, and that is the deliberate part. The write target
has to be one the SHDR adapter NEVER feeds, or the assertion races the stream --
but it must NOT be the existing never-fed fixture_block: the first successful
write takes an item off UNAVAILABLE for the life of the container, which would
silently rob Read_maps_an_unavailable_observation_to_BadNoCommunication of its
subject. So fixture_writeback (free-text EVENT, PROGRAM_COMMENT) is a separate,
dedicated target, overridable via MTCONNECT_WRITE_TARGET for a run pointed at a
real machine tool.
The three legs:
* Round trip -- driver write accepted, then the injected value read back off
/current over plain HTTP (not through the parser under test) AND through the
driver's own ReadAsync. The value carries a TickCount64 suffix: the Agent
keeps an injected observation for the container's life, so a constant would
be satisfied by a previous run's leftover.
* Agent refusal -> BadCommunicationError. The design doc doubted this leg was
constructible ("an id in the probe but refused by the agent"); it is, and the
mechanism is BuildWriteTargets. Write targets are derived from the tags the
BINDING serves, with the device resolved from the probe model and falling
back to the configured deviceName -- so an authored tag naming an id the
Agent never declared, on a driver whose deviceName IS set, resolves to a real
URL and is POSTed. That is exactly the shape a stale tag has after a DataItem
is renamed. The second half of the test is the falsifiability control: the
SAME unknown id with NO deviceName has no URL and must be refused locally as
BadNodeIdUnknown. Two different codes is what proves the first write actually
reached the Agent rather than being short-circuited into a look-alike.
* Disabled gate -- write.enabled absent returns BadNotWritable AND /current is
unchanged from the snapshot taken just before, which is what distinguishes
"refused" from "reported refused and sent anyway".
RAN LIVE, not just compiled: the fixture was brought up locally (OrbStack,
MTCONNECT_AGENT_HOST_PORT=5555 -- macOS AirPlay squats :5000) and the whole
suite passed 15/15, 0 skipped. Evidence beyond the green: the Agent reports
<ProgramComment dataItemId="fixture_writeback">OTOPCUA-WRITE-2CBCB530</...> and
its log carries "Error processing request:
/OtFixtureCnc?otopcua_no_such_data_item_2CBCB3D9=refuse-me" -- the refusal leg
demonstrably went to the wire. Offline (no Agent) the suite is 15 skipped, 0
failed; build 0 warnings / 0 errors.
Note for anyone reading agent.cfg: BufferSize = 14 is an EXPONENT (2^14 = 16384
observations), not a 14-deep ring, and /current is answered from the Agent's
per-DataItem checkpoint anyway -- so eviction is not a hazard for a write
read-back even on this busy fixture stream.
LiveOptions/ConfigJson/LiveDriverAsync gained writeEnabled + deviceName
parameters, both defaulted off/null so every pre-existing test still runs
against the shipped read-only driver whatever the Agent's AllowPut says. The
config JSON sources write.enabled FROM the options object, so the parsed config
can never disagree with the options a test thinks it built.
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.