CompiledScriptCache<TContext, TResult> — source-hash-keyed cache of compiled evaluators. Roslyn compilation is the most expensive step in the evaluator pipeline (5-20ms per script depending on size); re-compiling on every value-change event would starve the engine. ConcurrentDictionary of Lazy<ScriptEvaluator> with ExecutionAndPublication mode ensures concurrent callers never double-compile even on a cold cache race. Failed compiles evict the cache entry so an Admin UI retry with corrected source actually recompiles (otherwise the cached exception would persist). Whitespace-sensitive hash — reformatting a script misses the cache on purpose, simpler than AST-canonicalize and happens rarely. No capacity bound because virtual-tag + alarm scripts are config-DB bounded (thousands, not millions); if scale pushes past that in v3 an LRU eviction slots in behind the same API. TimedScriptEvaluator<TContext, TResult> — wraps a ScriptEvaluator with a per-evaluation wall-clock timeout (default 250ms per Phase 7 plan Stream A.4, configurable per tag so slower backends can widen). Critical implementation detail: the underlying Roslyn ScriptRunner executes synchronously on the calling thread for CPU-bound user scripts, returning an already-completed Task before the caller can register a timeout. Naive `Task.WaitAsync(timeout)` would see the completed task and never fire. Fix: push evaluation to a thread-pool thread via Task.Run, so the caller's thread is free to wait and the timeout reliably fires after the configured budget. Known trade-off (documented in the class summary): when a script times out, the underlying evaluation task continues running on the thread-pool thread until Roslyn returns; in the CPU-bound-infinite-loop case it's effectively leaked until the runtime decides to unwind. Tighter CPU budgeting would require an out-of-process script runner (v3 concern). In practice the timeout + structured warning log surfaces the offending script so the operator fixes it, and the orphan thread is rare. Caller-supplied CancellationToken is honored and takes precedence over the timeout, so driver-shutdown paths see a clean OperationCanceledException rather than a misclassified ScriptTimeoutException. ScriptTimeoutException carries the configured Timeout and a diagnostic message pointing the operator at ctx.Logger output around the failure plus suggesting widening the timeout, simplifying the script, or moving heavy work out of the evaluation path. The virtual-tag engine (Stream B) will catch this and map the owning tag's quality to BadInternalError per Phase 7 decision #11, logging a structured warning with the offending script name. Tests: CompiledScriptCacheTests (10) — first-call compile, identical-source dedupe to same instance, different-source produces different evaluator, whitespace-sensitivity documented, cached evaluator still runs correctly, failed compile evicted for retry, Clear drops entries, concurrent GetOrCompile of the same source deduplicates to one instance, different TContext/TResult use separate cache instances, null source rejected. TimedScriptEvaluatorTests (9) — fast script completes under timeout, CPU-bound script throws ScriptTimeoutException, caller cancellation takes precedence over timeout (shutdown path correctness), default 250ms per plan, zero/negative timeout rejected at construction, null inner rejected, null context rejected, user-thrown exceptions propagate unwrapped (not conflated with timeout), timeout exception message contains diagnostic guidance. Full suite: 48/48 green (29 from A.1 + 19 new). Next: Stream A.3 wires the dedicated scripts-*.log Serilog rolling sink + structured-property filtering + companion-WARN enricher to the main log, closing out Stream A. 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.