ScriptContext abstract base defines the API user scripts see as ctx — GetTag(string) returns DataValueSnapshot so scripts branch on quality naturally, SetVirtualTag(string, object?) is the only write path virtual tags have (OPC UA client writes to virtual nodes rejected separately in DriverNodeManager per ADR-002), Now + Logger + Deadband static helper round out the surface. Concrete subclasses in Streams B + C plug in actual tag backends + per-script Serilog loggers.
ScriptSandbox.Build(contextType) produces the ScriptOptions for every compile — explicit allow-list of six assemblies (System.Private.CoreLib / System.Linq / Core.Abstractions / Core.Scripting / Serilog / the context type's own assembly), with a matching import list so scripts don't need using clauses. Allow-list is plan-level — expanding it is not a casual change.
DependencyExtractor uses CSharpSyntaxWalker to find every ctx.GetTag("literal") and ctx.SetVirtualTag("literal", ...) call, rejects every non-literal path (variable, concatenation, interpolation, method-returned). Rejections carry the exact TextSpan so the Admin UI can point at the offending token. Reads + writes are returned as two separate sets so the virtual-tag engine (Stream B) knows both the subscription targets and the write targets.
Sandbox enforcement turned out needing a second-pass semantic analyzer because .NET 10's type forwarding makes assembly-level restriction leaky — System.Net.Http.HttpClient resolves even with WithReferences limited to six assemblies. ForbiddenTypeAnalyzer runs after Roslyn's Compile() against the SemanticModel, walks every ObjectCreationExpression / InvocationExpression / MemberAccessExpression / IdentifierName, resolves to the containing type's namespace, and rejects any prefix-match against the deny-list (System.IO, System.Net, System.Diagnostics, System.Reflection, System.Threading.Thread, System.Runtime.InteropServices, Microsoft.Win32). Rejections throw ScriptSandboxViolationException with the aggregated list + source spans so the Admin UI surfaces every violation in one round-trip instead of whack-a-mole. System.Environment explicitly stays allowed (read-only process state, doesn't persist or leak outside) and that compromise is pinned by a dedicated test.
ScriptGlobals<TContext> wraps the context as a named field so scripts see ctx instead of the bare globalsType-member-access convention Roslyn defaults to — keeps script ergonomics (ctx.GetTag) consistent with the AST walker's parse shape and the Admin UI's hand-written type stub (coming in Stream F). Generic on TContext so Stream C's alarm-predicate context with an Alarm property inherits cleanly.
ScriptEvaluator<TContext, TResult>.Compile is the three-step gate: (1) Roslyn compile — throws CompilationErrorException on syntax/type errors with Location-carrying diagnostics; (2) ForbiddenTypeAnalyzer semantic pass — catches type-forwarding sandbox escapes; (3) delegate creation. Runtime exceptions from user code propagate unwrapped — the virtual-tag engine in Stream B catches + maps per-tag to BadInternalError quality per Phase 7 decision #11.
29 unit tests covering every surface: DependencyExtractorTests has 14 theories — single/multiple/deduplicated reads, separate write tracking, rejection of variable/concatenated/interpolated/method-returned/empty/whitespace paths, ignoring non-ctx methods named GetTag, empty-source no-op, source span carried in rejections, multiple bad paths reported in one pass, nested literal extraction. ScriptSandboxTests has 15 — happy-path compile + run, SetVirtualTag round-trip, rejection of File.IO + HttpClient + Process.Start + Reflection.Assembly.Load via ScriptSandboxViolationException, Environment.GetEnvironmentVariable explicitly allowed (pinned compromise), script-exception propagation, ctx.Now reachable, Deadband static reachable, LINQ Where/Sum reachable, DataValueSnapshot usable in scripts including quality branches, compile error carries source location.
Next two PRs within Stream A: A.2 adds the compile cache (source-hash keyed) + per-evaluation timeout wrapper; A.3 wires the dedicated scripts-*.log Serilog rolling sink with structured-property filtering + the companion-warning enricher to the main log.
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.