Per-kind override shape: each hook receives the pre-filtered nodesToProcess list (NodeHandles for nodes this manager claimed), iterates them, resolves handle.NodeId.Identifier to the driver-side full reference string, and dispatches to the right IHistoryProvider method. Write back into the outer results + errors slots at handle.Index (not the local loop counter — nodesToProcess is a filtered subset of nodesToRead, so indexing by the loop counter lands in the wrong slot for mixed-manager batches). WriteResult helper sets both results[i] AND errors[i]; this matters because MasterNodeManager merges them and leaving errors[i] at its default (BadHistoryOperationUnsupported) overrides a Good result with Unsupported on the wire — this was the subtle failure mode that masked a correctly-constructed HistoryData response during debugging. Failure-isolation per node: NotSupportedException from a driver that doesn't implement a particular HistoryProvider method translates to BadHistoryOperationUnsupported in that slot; generic exceptions log and surface BadInternalError; unresolvable NodeIds get BadNodeIdUnknown. The batch continues unconditionally. Aggregate mapping: MapAggregate translates ObjectIds.AggregateFunction_Average / Minimum / Maximum / Total / Count to the driver's HistoryAggregateType enum. Null for anything else (e.g. TimeAverage, Interpolative) so the handler surfaces BadAggregateNotSupported at the batch level — per Part 13, one unsupported aggregate means the whole request fails since ReadProcessedDetails carries one aggregate list for all nodes. BuildHistoryData wraps driver DataValueSnapshots as Opc.Ua.HistoryData in an ExtensionObject; BuildHistoryEvent wraps HistoricalEvents as Opc.Ua.HistoryEvent with the canonical BaseEventType field list (EventId, SourceName, Message, Severity, Time, ReceiveTime — the order OPC UA clients that didn't customize the SelectClause expect). ToDataValue preserves null SourceTimestamp (Galaxy historian rows often carry only ServerTimestamp) — synthesizing a SourceTimestamp would lie about actual sample time. Two address-space changes were required to make the stack dispatch reach the per-kind hooks at all: (1) historized variables get AccessLevels.HistoryRead added to their AccessLevel byte — the base's early-gate check on (variable.AccessLevel & HistoryRead != 0) was rejecting requests before our override ever ran; (2) the driver-root folder gets EventNotifiers.HistoryRead | SubscribeToEvents so HistoryReadEvents can target it (the conventional pattern for alarm-history browse against a driver-owned object). Document the 'set both bits' requirement inline since it's not obvious from the surface API. OpcHistoryReadResult alias: Opc.Ua.HistoryReadResult (service-layer per-node result) collides with Core.Abstractions.HistoryReadResult (driver-side samples + continuation point) by type name; the alias 'using OpcHistoryReadResult = Opc.Ua.HistoryReadResult' keeps the override signatures unambiguous and the test project applies the mirror pattern for its stub driver impl. Tests — DriverNodeManagerHistoryMappingTests (12 new Category=Unit cases): MapAggregate translates each supported aggregate NodeId via reflection-backed theory (guards against the stack renaming AggregateFunction_* constants); returns null for unsupported NodeIds (TimeAverage) and null input; BuildHistoryData wraps samples with correct DataValues + SourceTimestamp preservation; BuildHistoryEvent emits the 6-element BaseEventType field list in canonical order (regression guard for a future 'respect the client's SelectClauses' change); null SourceName / Message translate to empty-string Variants (nullable-Variant refactor trap); ToDataValue preserves StatusCode + both timestamps; ToDataValue leaves SourceTimestamp at default when the snapshot omits it. HistoryReadIntegrationTests (5 new Category=Integration): drives a real OPC UA client Session.HistoryRead against a fake HistoryDriver through the running server. Covers raw round-trip (verifies per-node DataValue ordering + values); processed with Average aggregate (captures the driver's received aggregate + interval, asserting MapAggregate routed correctly); unsupported aggregate (TimeAverage → BadAggregateNotSupported); at-time (forwards the per-timestamp list); events (BaseEventType field list shape, SelectClauses populated to satisfy the stack's filter validator). Server.Tests Unit: 55 pass / 0 fail (43 prior + 12 new mapping). Server.Tests Integration: 14 pass / 0 fail (9 prior + 5 new history). Full solution build clean, 0 errors. lmx-followups.md #1 updated to 'DONE (PRs 35 + 38)' with two explicit deferred items: continuation-point plumbing (driver returns null today so pass-through is fine) and per-SelectClause evaluation in HistoryReadEvents (clients with custom field selections get the canonical BaseEventType layout today). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
LmxOpcUa
OPC UA server and cross-platform client tools for AVEVA System Platform (Wonderware) Galaxy. The server exposes Galaxy tags via MXAccess as an OPC UA address space. The client stack provides a shared library, CLI tool, and Avalonia desktop application for browsing, reading/writing, subscriptions, alarms, and historical data.
Architecture
OPC UA Clients
(CLI, Desktop UI, 3rd-party)
|
v
+-----------------+ +------------------+ +-----------------+
| Galaxy Repo DB |---->| OPC UA Server |<--->| MXAccess Client |
| (SQL Server) | | (address space) | | (STA + COM) |
+-----------------+ +------------------+ +-----------------+
| |
+-------+--------+ +---------+---------+
| Status Dashboard| | Historian Runtime |
| (HTTP/JSON) | | (SQL Server) |
+----------------+ +-------------------+
Contained Name vs Tag Name
| Browse Path (contained names) | Runtime Reference (tag name) |
|---|---|
TestMachine_001/DelmiaReceiver/DownloadPath |
DelmiaReceiver_001.DownloadPath |
TestMachine_001/MESReceiver/MoveInBatchID |
MESReceiver_001.MoveInBatchID |
Server
The OPC UA server runs on .NET Framework 4.8 (x86) and bridges the Galaxy runtime to OPC UA clients.
Server Prerequisites
- .NET Framework 4.8 SDK
- AVEVA System Platform with ArchestrA Framework installed
- Galaxy repository database (SQL Server, Windows Auth)
- MXAccess COM registered (
LMXProxy.LMXProxyServer) - Wonderware Historian (optional, for historical data access)
- Windows (required for COM interop and MXAccess)
Build and Run Server
dotnet restore ZB.MOM.WW.LmxOpcUa.slnx
dotnet build src/ZB.MOM.WW.LmxOpcUa.Host
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Host
The server starts on opc.tcp://localhost:4840/LmxOpcUa with the None security profile by default. Configure Security.Profiles in appsettings.json to enable Basic256Sha256-Sign or Basic256Sha256-SignAndEncrypt for transport security. See Security Guide.
Install as Windows Service
cd src/ZB.MOM.WW.LmxOpcUa.Host/bin/Debug/net48
ZB.MOM.WW.LmxOpcUa.Host.exe install
ZB.MOM.WW.LmxOpcUa.Host.exe start
Service logon requirement: The service must run under a Windows account that has access to the AVEVA Galaxy and Historian. The default LocalSystem account can connect to MXAccess and SQL Server but cannot authenticate with the Historian SDK (HCAP). Configure the service to "Log on as" a domain or local user that is a recognized ArchestrA platform user. This can be set in services.msc or during install with ZB.MOM.WW.LmxOpcUa.Host.exe install -username DOMAIN\user -password ***.
Run Server Tests
dotnet test tests/ZB.MOM.WW.LmxOpcUa.Tests
dotnet test tests/ZB.MOM.WW.LmxOpcUa.IntegrationTests
Client Stack
The client stack is cross-platform (.NET 10) and consists of three projects sharing a common IOpcUaClientService abstraction. No AVEVA software or COM is required — the clients connect to any OPC UA server.
Client Prerequisites
- .NET 10 SDK
- No platform-specific dependencies (runs on Windows, macOS, Linux)
Build All Clients
dotnet build src/ZB.MOM.WW.LmxOpcUa.Client.Shared
dotnet build src/ZB.MOM.WW.LmxOpcUa.Client.CLI
dotnet build src/ZB.MOM.WW.LmxOpcUa.Client.UI
Run Client Tests
dotnet test tests/ZB.MOM.WW.LmxOpcUa.Client.Shared.Tests
dotnet test tests/ZB.MOM.WW.LmxOpcUa.Client.CLI.Tests
dotnet test tests/ZB.MOM.WW.LmxOpcUa.Client.UI.Tests
Client CLI
# Connect
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- connect -u opc.tcp://localhost:4840/LmxOpcUa
# Browse Galaxy hierarchy
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- browse -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=ZB" -r -d 5
# Read a tag
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- read -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=TestMachine_001.MachineID"
# Write a tag
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- write -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=TestChildObject.TestString" -v "Hello"
# Subscribe to changes
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- subscribe -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=TestChildObject.TestInt" -i 500
# Read historical data
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- historyread -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=TestMachine_001.TestHistoryValue" --start "2026-03-25" --end "2026-03-30"
# Subscribe to alarm events
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- alarms -u opc.tcp://localhost:4840/LmxOpcUa -n "ns=3;s=TestMachine_001" --refresh
# Query redundancy state
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.CLI -- redundancy -u opc.tcp://localhost:4840/LmxOpcUa
Client UI
dotnet run --project src/ZB.MOM.WW.LmxOpcUa.Client.UI
The desktop application provides browse tree, subscriptions, alarm monitoring, history reads, and write dialogs. See Client UI Documentation for details.
Project Structure
src/
ZB.MOM.WW.LmxOpcUa.Host/ OPC UA server (.NET Framework 4.8, x86)
Configuration/ Config binding and validation
Domain/ Interfaces, DTOs, enums, mappers
Historian/ Wonderware Historian data source
Metrics/ Performance tracking (rolling P95)
MxAccess/ STA thread, COM interop, subscriptions
GalaxyRepository/ SQL queries, change detection
OpcUa/ Server, node manager, address space, alarms, diff
Status/ HTTP dashboard, health checks
ZB.MOM.WW.LmxOpcUa.Client.Shared/ Shared OPC UA client library (.NET 10)
ZB.MOM.WW.LmxOpcUa.Client.CLI/ Command-line client (.NET 10)
ZB.MOM.WW.LmxOpcUa.Client.UI/ Avalonia desktop client (.NET 10)
tests/
ZB.MOM.WW.LmxOpcUa.Tests/ Server unit + integration tests
ZB.MOM.WW.LmxOpcUa.IntegrationTests/ Server integration tests (live DB)
ZB.MOM.WW.LmxOpcUa.Client.Shared.Tests/ Shared library tests
ZB.MOM.WW.LmxOpcUa.Client.CLI.Tests/ CLI command tests
ZB.MOM.WW.LmxOpcUa.Client.UI.Tests/ UI ViewModel + headless tests
gr/ Galaxy repository docs, SQL queries, schema
Documentation
Server
| Component | Description |
|---|---|
| OPC UA Server | Endpoint, sessions, security policy, server lifecycle |
| Address Space | Hierarchy nodes, variable nodes, primitive grouping, NodeId scheme |
| Galaxy Repository | SQL queries, deployed package chain, change detection |
| MXAccess Bridge | STA thread, COM interop, subscriptions, reconnection |
| Data Type Mapping | Galaxy to OPC UA types, arrays, security classification |
| Read/Write Operations | Value reads, writes, access level enforcement, array element writes |
| Subscriptions | Ref-counted MXAccess subscriptions, data change dispatch |
| Alarm Tracking | AlarmConditionState nodes, InAlarm monitoring, event reporting |
| Historical Data Access | Historian data source, HistoryReadRaw, HistoryReadProcessed |
| Incremental Sync | Diff computation, subtree teardown/rebuild, subscription preservation |
| Configuration | appsettings.json binding, feature flags, validation |
| Status Dashboard | HTTP server, health checks, metrics reporting |
| Service Hosting | TopShelf, startup/shutdown sequence, error handling |
| Security | Transport security profiles, certificate trust, production hardening |
| Redundancy | Non-transparent warm/hot redundancy, ServiceLevel, paired deployment |
Client
| Component | Description |
|---|---|
| Client CLI | Connect, browse, read, write, subscribe, historyread, alarms, redundancy commands |
| Client UI | Avalonia desktop client: browse, subscribe, alarms, history, write values |
Reference
- Galaxy Repository Queries — SQL queries for hierarchy, attributes, and change detection
- Data Type Mapping — Galaxy to OPC UA type mapping with security classification
License
Internal use only.