romanett
e61ad4b306
# Description Part 16 §B.3 places `HasSubStateMachine` on the parent **state** node, but the fluent builder attached it to the state-machine **root** because `FluentFiniteStateMachineState` never materialized state nodes at all. Investigating #3821 showed the gap was wider than the reference placement: 1. **No state nodes existed.** The NodeId written into `CurrentState/Id` — `new NodeId(stateId, ElementNamespaceIndex)` — was **dangling**: no node with that id was in the address space. 2. **`AvailableStates` was never populated**, so `GetAvailableStatesAsync` returned empty against a fluent-built server. 3. **The whole client discovery chain was therefore dead.** `ObserveEffectiveStateAsync` enumerates `AvailableStates` and browses `HasSubStateMachine` from each state node — it found nothing. The client side was already spec-correct; only the server deviated. 4. **`HasSubStateMachine` is non-hierarchical** (a subtype of `NonHierarchicalReferences`, `i=32`). Using it as the sub-SM's `BaseInstanceState.ReferenceTypeId` left the sub-SM unreachable from a hierarchical browse of the machine. ## What changed **Element nodes are materialized.** Definition-mode machines now create one `StateType` node per declared state and one `TransitionType` node per declared transition — each a `HasComponent` child carrying `StateNumber` / `TransitionNumber`, with the §B.4 `FromState` / `ToState` / `HasEffect` references and `HasCause` added by `WithCause`. `AvailableStates`, `AvailableTransitions` and `LastTransition` are populated, so `CurrentState/Id` and `LastTransition/Id` resolve to real, browsable nodes. NodeIds are per-instance, so several machines built from one definition coexist. **`HasSubStateMachine` moved to the state node**, with the inverse `SubStateMachineOf`, and the sub-SM is attached as a `HasComponent` child (fixing 4). **Core gains element-id mapping hooks.** `GetCurrentStateId` / `UpdateStateVariable` / `UpdateTransitionVariable` hard-coded the numeric form and were non-virtual, so a subclass could not redirect them. They now route through `public virtual` `GetStateNodeId` / `GetStateId` / `GetTransitionNodeId` / `GetTransitionId`, whose defaults reproduce the previous `(elementId, ElementNamespaceIndex)` convention **exactly** — every stack-shipped and generator-emitted machine is unaffected, and there is a regression test asserting that. **Generated machines report their model namespace.** The generator now emits an `ElementNamespaceUri` override on `FiniteStateMachineType` subtypes, taken from the nearest type that actually *declares* state children — a subtype that only adds behaviour inherits its elements, and their namespace, from its base. **Ordering and validation fixes.** `WithSubStateMachine` and `WithInitialState` are now order-independent (previously, attaching a sub-SM before setting the initial state left the child suspended until the parent left and re-entered the state — silently). `WithSubStateMachine` validates `parentStateId`, and the builder rejects duplicate element browse names, since element NodeIds are now derived from them. ## A defect this surfaced Code that assembles nodes with the generated `CreateInstanceOf<Type>` factories never calls `NodeState.CreateAsPredefinedNode`, so `OnBeforeCreate` / `OnAfterCreate` are skipped for the entire subtree — and `OnAfterCreate` is the only place a state machine resolves its element namespace. It is also where `ConditionState` binds its `Enable` / `Disable` / `AddComment` handlers and `AlarmConditionState` binds the shelving methods, so the impact is broader than state machines. This PR fixes only the two call sites it depends on — DI's `SoftwareUpdateFacetWiring` and Robotics' `RoboticsOperationBuilder`. **The repository-wide audit is deliberately left out of scope and tracked in #4320** (24 files call these factories; none completed the lifecycle). The Robotics regression had no test coverage at all, so an assertion on `CurrentState/Id` was added and verified to fail without the fix. ## Breaking changes - Sub-state machines are **no longer browsable from the state-machine root**. Callers passing a machine's `ObjectId` to `GetSubStateMachineAsync` must pass a state NodeId instead — from `GetAvailableStatesAsync` or a snapshot's `CurrentStateId`. - `CurrentState/Id` for fluent machines changes from the numeric form to the materialized node's id. Code reading a numeric id out of it should call `FiniteStateMachineState.GetStateId` rather than parsing the identifier. - Generated machines qualify `CurrentState/Id` / `LastTransition/Id` with their companion-spec namespace instead of the OPC UA one. Documented in `docs/WhatsNewIn2.0.md` and `docs/StateMachines.md`. ## Notes for reviewers - Adding `virtual` to the `FiniteStateMachineState` members is a binary (not source) breaking change — assumed acceptable on the 2.0 line, but worth confirming against the compatibility policy. - Address-space cost is one node plus one property per declared state and transition, per machine instance; called out in the docs for servers instantiating many machines. - `AvailableTransitions` is modelled as a `HasComponent` `BaseDataVariable` (matching the standard NodeSet and what the client's browse path expects), not a Property. ## Related Issues - Fixes #3821 - Surfaced #4320 (node create lifecycle audit — not addressed here) ## Checklist - [ ] I have signed the [CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf) and read the [CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md) doc. - [x] I have added tests that prove my fix is effective or that my feature works and increased code coverage. - [x] I have added all necessary documentation. - [x] I have verified that my changes do not introduce (new) build or analyzer warnings. - [ ] I ran **all** tests locally using the **UA.slnx** solution against at least .net **framework** and .net **10**, and all passed. - [ ] I fixed **all** failing and flaky tests in the CI pipelines and **all** CodeQL warnings. - [ ] I have addressed **all** PR feedback received. ### Test runs (net10.0) | Suite | Result | |---|---| | `Opc.Ua.Server.Tests` (full) | 4734 passed, 5 skipped | | `Opc.Ua.SourceGeneration.Core.Tests` | 3780 passed | | `Opc.Ua.SourceGeneration.Tests` | 132 passed | | `Opc.Ua.SourceGeneration.Stack.Tests` | 94 passed | | `Opc.Ua.Types.Tests` | 8763 passed | | `Opc.Ua.Robotics.Tests` | 540 passed | | `Opc.Ua.Robotics.Intent.Tests` | 22 passed | | `Opc.Ua.Di.Tests` | 424 passed | | `Opc.Ua.ISA95.Tests` | 136 passed | | `Opc.Ua.Aas.Tests` | 670 passed | | `Opc.Ua.Positioning.Tests` | 69 passed | | `Opc.Ua.Client.Tests` (StateMachines) | 36 passed | Only net10.0 was run locally; the .NET Framework leg is left to CI, hence the unchecked box above. --------- Co-authored-by: Claude Opus 5 <noreply@anthropic.com> Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: marcschier <11168470+marcschier@users.noreply.github.com>
OPC Foundation UA .NET Standard Reference Server
Introduction
This document is referring to the CTT version 1.04.9.398.
This OPC Server is designed to be the default OPC UA Server when opening the OPC UA Compliance Test Tool and it uses an address-space that matches the design of the UACTT and the requirements for OPC UA compliance testing.
It uses the OPC Foundation UA .NET Standard Library. Therefore it supports both the opc.tcp and https transports. There is a .NET framework based server with UI and a .NET Core console version of the server which runs on any OS supporting .NET Standard 2.1 or .NET 8.0 and later.
How to build and run the Windows OPC UA Reference Server with UACTT
- Open the solution UA.slnx with Visual Studio 2026.
- Choose the project
Reference Serverin the Solution Explorer and set it with a right click asStartup Project. - Hit
F5to build and execute the sample.
How to build and run the console OPC UA Reference Server on Windows, Linux and iOS
This section describes how to run the ConsoleReferenceServer.
Please follow instructions in this article to setup the dotnet command line environment for your platform.
Start the server
- Open a command prompt.
- Navigate to the folder samples/Reference/ConsoleReferenceServer.
- To run the server sample type
dotnet run --project ConsoleReferenceServer.csproj. The server is now running and waiting for the connection of the UACTT.
UACTT test certificates
The reference server always rejects new client certificates and requires that the UACTT certificates are in appropriate folders.
- The console server certificates are stored in %LocalApplicationData%/OPC Foundation/pki.
- The Windows .NET framework server stores the certificates in %CommonApplicationData%\OPC Foundation\pki.
- %CommonApplicationData% maps to the path set by the environment variable ProgramData on Windows.
- %LocalApplicationData% maps to a hidden location in the user home folder and depends on the target platform. See Certificates for more information.
Certificate stores
Under pki, the following stores contain certificates under certs, CRLs under crl or private keys under private.
- own contains the reference server public certificate and private key.
- rejected contains the rejected client certificates. To trust a client certificate, copy the rejected certificate to the trusted/certs folder.
- trusted contains trusted client and CAs certificates and CRLs.
- issuer contains CAs certificates and CRLs needed for validation.
- trustedUser contains trusted user and user CA certificates and CRLs.
- issuerUser contains user CA certificates and CRLs needed for validation of the certificate chains.
Placing the UACTT certificates
CTT creates a PKI folder in a new project. There is a subfolder copyToServer which contains the application and user identity certificates. Copy the ApplicationInstance_PKI certificates for testing with the UACTT to the following stores:
- trusted/certs: trusted certificates
- trusted/crl: revocation lists of trusted certificates
- issuer/certs: issuer certificates
- issuer/crl: revocation lists of issuer certificates
Copy the X509UserIdentity_PKI certificates for testing with the UACTT to the following stores:
- trustedUser/certs: trusted user certificates
- trustedUser/crl: revocation lists of trusted user certificates
- issuerUser/certs: user issuer certificates
- issuerUser/crl: revocation lists of user issuer certificates
UACTT Testing
Download and install the OPC UA Compliance Test Tool.
Note: Access to the UACTT is granted to OPC Foundation Corporate Members.
UACTT sample configuration
A sample configuration for the UACTT Version 1.04.9.398 can be found in UAReferenceServer.ctt.xml. Originally the reference server was certified only against the Standard UA Server profile, the Method Server Facet and the DataAccess Server Facet, in addition to all security related profiles. During release testing all Conformance Units should be enabled / checked.
Enabling Alarms & Conditions
The address space for Alarms contains a Start method which needs to be called to produce alarms for CTT testing. The method is called from a connected client.
The ConsoleReferenceServer has also a command line option -ctt which starts the Alarms when the server is started. The following Alarm instances are available for monitoring:
AlarmConditionTypeDiscrepancyAlarmTypeLimitAlarmTypeExclusiveLimitAlarmTypeExclusiveDeviationAlarmTypeExclusiveRateOfChangeAlarmTypeNonExclusiveLimitAlarmTypeNonExclusiveDeviationAlarmTypeNonExclusiveRateOfChangeAlarmTypeDiscreteAlarmTypeSystemOffNormalAlarmTypeExclusiveLevelAlarmTypeNonExclusiveLevelAlarmTypeOffNormalAlarmType
Known missing Tests and Issues
Depending on the setup in the provided project configuration, unsupported profiles should be skipped. At the time of writing (1.4.368) the following tests, profiles or facets are not yet covered or not configured due to issues:
- no support for events, historian and only a few basic Alarms & Conditions.
- Decimal type causes crash of CTT (needs investigation)
- no Image / Enumeration scalar test cases
- Arrays may not include Variant (needs investigation)
- no ArrayItemType implemented
- multiple hierarchical references test node missing
- deprecated security profiles support for SHA1/1k RSA keys implemented not according to certification. SHA1/1k keys can only be turned on/off for all profiles, not just for the deprecated profiles.
- Monitored Items with array are failing a few test cases.
It is recommended to run the server as retail build with disabled logging, to avoid side effects due to timing artifacts when log entries are written to a disk drive.
Running the CTT against a Docker container
Please refer to the Docker container of the Reference Server documentation page. Once setup to map the certificate store and the configuration to a local folder, follow the instructions above to copy the certificates to the PKI and get started.
Finding the Address Space Configuration Code
- Project: Reference Server
- File: ReferenceNodeManager.cs
- Method: CreateAddressSpace
Finding the UA Services
- Project: Opc.Ua.Server
- File: StandardServer.cs