UA-.NETStandard/docs/AutoID.md

AutoID Devices

The AutoID packages implement OPC 30010 OPC UA for AutoID Devices (release 1.01, 2020-06-18): RFID readers, OCR readers, optical (barcode) readers and verifiers, and real-time locating systems (RTLS), with their scan results, tag access methods and diagnostics events.

Package	What it adds
Opc.Ua.AutoID	The information model: node states, DataTypes, identifiers, encodeables and client proxies
Opc.Ua.AutoID.Server	Reader hosting on the Device Integration node manager, a provider contract for the reader hardware, the OPC 30010 methods and events, simulated readers
Opc.Ua.AutoID.Client	Reader discovery, typed scan and tag calls, device snapshots and an asynchronous stream of events
Opc.Ua.Mcp.AutoID	Nine bounded MCP tools; no tool changes a tag

The AutoID sample runs a simulated RFID reader end to end.

Contents

• Model and dependencies
• What the model package contains
• Loading the model
• Scan data and scan results
• Hosting readers
  • Coexisting with a server that already owns DI
  • Placement
  • Direct composition and lifetime
• Providers
• Behavior of the methods
• Events
• Conformance
• Client
• MCP tools
• Sample
• Specification notes
• Provenance

Model and dependencies

Item	Value
Package	OPCFoundation.NetStandard.Opc.Ua.AutoID
Model URI	http://opcfoundation.org/UA/AutoID/
Model version	1.01, published 2020-06-18
Required models	OPC UA 1.03, Device Integration 1.01 (lower bounds)
Generated CLR namespace	Opc.Ua.AutoID
Source	UA-Nodeset latest/AutoID

AutoIdDeviceType derives from the DI DeviceType, so the package references Opc.Ua.Di and loads the DI model the stack ships, which is newer than the required 1.01.

What the model package contains

• The device types AutoIdDeviceType (abstract), RfidReaderDeviceType, OcrReaderDeviceType, OpticalReaderDeviceType, OpticalVerifierDeviceType and RtlsDeviceType, with their methods (Scan, ScanStart, ScanStop, ReadTag, WriteTag, WriteTagID, KillTag, LockTag, SetTagPassword, GetLocation, ...) as typed method states.
• The event types AutoIdScanEventType with one subtype per reader kind, AutoIdDiagnosticsEventType, AutoIdAccessEventType, RfidAccessEventType, AutoIdLogEntryEventType and AutoIdPresenceEventType.
• The DataTypes: the ScanData and Location unions, the abstract ScanResult with RfidScanResult, OcrScanResult, OpticalScanResult, OpticalVerifierScanResult and RtlsLocationResult, the access results AccessResult and RfidAccessResult, ScanSettings, RfidSighting, ScanDataEpc, the coordinate structures and six enumerations.
• AutoIdModel (model identity, GetNamespaceUris()) and the AddAutoIdTypeSystem registration overloads.

The scan event subtypes and RfidAccessEventType narrow the DataType of their ScanResult or AccessResult property to a structure subtype. The generated states expose the property with that type, for example RfidScanEventState.ScanResult is a PropertyState<ArrayOf<RfidScanResult>>.

Loading the model

using Opc.Ua;
using Opc.Ua.AutoID;

// Encodeables (DI and AutoID); the caller commits the builder.
messageContext.Factory.Builder.AddAutoIdTypeSystem().Commit();

// Type nodes for a node manager's predefined nodes.
var predefinedNodes = new NodeStateCollection();
predefinedNodes.AddAutoIdTypeSystem(systemContext);

// Typed node states for instances of the AutoID types.
nodeStateFactory.AddAutoIdTypeSystem();

AddAutoIdTypeSystem loads DI before AutoID, registers missing namespaces and skips roots that are already present, so it can be combined with other models that also load DI.

Scan data and scan results

ScanData is a union: SwitchField selects the ByteString, String, Epc or Custom arm. The scan and access results have optional fields; set the corresponding bits in EncodingMask to send them.

var result = new RfidScanResult
{
    CodeType = "EPC",
    ScanData = new ScanData
    {
        SwitchField = ScanDataFields.Epc,
        Epc = new ScanDataEpc { PC = 0x3000, UId = ByteString.From(epc) }
    },
    Timestamp = DateTimeUtc.Now,
    Sighting = [new RfidSighting { Antenna = 1, Strength = -52 }]
};

The NodeSet defines binary and XML encodings; JSON uses the DataType NodeIds.

Hosting readers

A server has one Device Integration DeviceSet, and exactly one node manager owns the DI namespace. Readers are therefore hosted in one of two ways:

• AddAutoId registers a node manager of its own that loads the DI and AutoID models and creates one device per reader below DeviceSet. Use it when AutoID is the only DI-based companion of the server.
• AddAutoIdModel loads the AutoID model into the Machinery node manager of AddMachinery, which then owns DI for every companion of the server; the readers are created in that manager, below the same DeviceSet as the machines, pumps or scales. See Coexisting with a server that already owns DI.

using Microsoft.Extensions.DependencyInjection;
using Opc.Ua.AutoID.Server;

services.AddOpcUa()
    .AddServer(options => { /* application name, endpoints, PKI */ })
    .AddAutoId(options => options.MaximumScanDuration = TimeSpan.FromSeconds(10))
    .ConfigureAutoId(async context =>
    {
        AutoIdReader reader = await context.Runtime
            .Reader(new QualifiedName("DockDoor1", context.Manager.InstanceNamespaceIndex), hardware)
            .WithDeviceInfo("Dock door antenna portal")
            .WithDeviceLocationName("Dock 1, gate A")
            .WithAntennaNames([new AntennaNameIdPair { AntennaId = 1, AntennaName = "Left post" }])
            .WithIdentification(nameplate => nameplate.SerialNumber = "R100-0001")
            .BuildAsync(context.CancellationToken);
    });

Reader(...) returns a builder; nothing is registered before BuildAsync. The builder materialises exactly the components the provider supports (a reader without a Scan provider has no Scan method), registers the device, makes it an event notifier and attaches the provider. A failure at any step is rolled back: the browse name can be used again and a provider the build owns (OwnsProvider()) is disposed. Concurrent builds of one name admit exactly one. Disposing the runtime (the node manager does so on shutdown) stops every reader's scans, detaches its provider and, for a provider the reader owns (OwnsProvider()), disposes it.

AutoIdServerOptions bounds what a client can ask for:

Option	Default	Effect
MaximumScanDuration	30 s	A synchronous Scan asking for more is Bad_InvalidArgument; a provider that does not return in time is cancelled and the call fails with Bad_Timeout
MaximumTagReadLength	65536	A longer ReadTag is Bad_InvalidArgument
MaximumScanResults	1000	More results fail the scan with Bad_ResponseTooLarge instead of being truncated
PublishAccessEvents	true	Whether commands that reach a tag raise access events
AdditionalNamespaceUris	none	Extra namespaces to register

The readers keep their scan state (Idle_0, Scanning_2, Busy_3, Error_1) in DeviceStatus. AutoIdReader.SetFaultedAsync(true) reports Error_1: new scans then return DEVICE_NOT_READY_17 and an active asynchronous scan stops. SetDeviceLocation moves the DeviceLocation of a mobile reader.

Coexisting with a server that already owns DI

AddAutoId claims the Device Integration address space like AddOpcUaDi, AddMachinery, AddPumps or AddScales, so registering it together with another DI owner, in either order, throws InvalidOperationException while the services are registered; the message names the current owner and the composition API. The check prevents duplicate DI address spaces: two DI owners would each load their own copy of DeviceSet, the server would route DeviceSet to the first one, and readers created in the second one would not be browsable.

To host readers next to machines, call AddAutoIdModel after AddMachinery and create the readers with ConfigureAutoIdFor<TNodeManager>. Other Machinery-based companions compose into the same owner:

using Microsoft.Extensions.DependencyInjection;
using Opc.Ua;
using Opc.Ua.AutoID.Server;
using Opc.Ua.Machinery.Server;

services.AddOpcUa()
    .AddServer(options => { /* application name, endpoints, PKI */ })
    .AddMachinery(options =>
    {
        options.Parts = MachineryParts.BuildingBlocks;
        options.InstanceNamespaceUri = "urn:acme:plant:instances";
    })
    .AddPumpsToMachinery()                       // optional, any *ToMachinery companion
    .AddAutoIdModel(options => options.MaximumScanDuration = TimeSpan.FromSeconds(10))
    .ConfigureMachinery(async (machinery, ct) =>
    {
        await machinery.AddMachine(new QualifiedName("Press1", machinery.InstanceNamespaceIndex))
            .WithIdentification(id =>
            {
                id.Manufacturer = new LocalizedText("Acme");
                id.SerialNumber = "PR-1";
                id.ProductInstanceUri = "urn:acme:press:1";
            })
            .BuildAsync(ct);
    })
    .ConfigureAutoIdFor<MachineryNodeManager>(async (context, ct) =>
    {
        AutoIdReader reader = await context.Runtime
            .Reader(new QualifiedName("PressInfeed", context.Runtime.InstanceNamespaceIndex), hardware)
            .WithDeviceInfo("Infeed portal of Press1")
            .BuildAsync(ct);
    });

Item	In the composed server
Node managers	The MachineryNodeManager alone; no AutoIdNodeManager is created
Device Integration model, DeviceSet	Loaded once by the Machinery owner's core model provider
AutoID model	Added to the owner by AutoIdModelProvider, with AdditionalNamespaceUris
Readers	Below the owner's DeviceSet (Organizes), NodeIds in MachineryServerOptions.InstanceNamespaceUri; take browse names from context.Runtime.InstanceNamespaceIndex. WithParent and AsComponentOf place a reader elsewhere and keep it reachable from DeviceSet, see Placement
Machines folder	Readers are devices, not machines, and are not added to it; AsComponentOf makes one a component of a machine
Methods, events, providers	As in the stand-alone server; the readers are event notifiers of the owner
Conformance	The runtime contributes the AutoID units and facets to the owner, which publishes them with the DI and Machinery ones
Lifetime	The owner disposes the runtime on shutdown: scans stop, providers detach, owned providers are disposed

Successive ConfigureAutoIdFor<MachineryNodeManager> delegates run in registration order in the DI post-setup pipeline. Register Machinery configuration first; then the reader callbacks run after it and share one AutoIdRuntime. context.Manager is the Machinery owner. ConfigureAutoIdFor<AutoIdNodeManager> works with AddAutoId and receives the stand-alone runtime, so configuration code can be shared by both hosting paths. Opc.Ua.AutoID.Server references only the Machinery model for component identification. A stand-alone server loads only the DI and AutoID models.

AddAutoIdToMachinery remains available as an obsolete alias of AddAutoIdModel in the same server package. It forwards options and model registration without claiming an owner or depending on the Machinery server package. Use AddAutoIdModel in new code and register owner configuration before dependent reader callbacks.

For a plain DI owner, use AddOpcUaDi().AddAutoIdModel() and ConfigureAutoIdFor<DiNodeManager>. The DI hosting guide describes AddDiModel<AutoIdModelProvider, TNodeManager>(configure), which combines model registration with an owner-targeted callback. The same helper accepts other companion providers and DI-derived owners without another integration package.

Placement

OPC 30010 does not say where readers live in the address space; the rules come from the specifications it builds on.

Rule	Source
"The DeviceSet Object is the starting point to locate Devices. It shall either directly or indirectly reference all instances of a subtype of ComponentType with a Hierarchical Reference." Every AutoID device type derives from DI DeviceType, a ComponentType.	OPC 10000-100 1.05.0 4.9; OPC 30010 6.1
"For complex Devices that are composed of various components that are also Devices, only the root instance shall be referenced from the DeviceSet Object."	OPC 10000-100 1.05.0 4.9
The Components object of a machine "directly references all identifiable components of a Machine", with HasComponent, and each component carries the 2:Identification add-in (HasAddIn) whose Manufacturer and SerialNumber are mandatory.	OPC 40001-1 1.04.2 11.1, 11.2 (Tables 27, 28), 8.3
Machinery and DI place no requirement on each other: a machine need not be in DeviceSet, and a device need not be in Machines.	OPC 40001-1 1.04.2, OPC 10000-100 1.05.0

The SDK applies them as follows:

Builder call	Where the reader is	Reference from DeviceSet
none (default)	Below DeviceSet	Organizes
WithParent(parent), DeviceSet reaches parent (for example another reader)	Below parent (HasComponent)	None: the reader is a component of a composed device whose root DeviceSet references
WithParent(parent), DeviceSet does not reach parent	Below parent (HasComponent)	Organizes to the outermost DI component in the parent chain, added by the owner
AsComponentOf(machine)	Below the machine's Components (HasComponent), with an Identification add-in	As for WithParent with the Components object as parent: usually Organizes, because a machine in Machines is not necessarily reachable from DeviceSet

Whether DeviceSet reaches the parent is decided when the reader is built, by following the forward hierarchical references of the owner's nodes. A child attached by a non-hierarchical reference, such as a condition by HasCondition, is no path from DeviceSet.

Where OPC 30010 is silent, these are SDK decisions: a reader is not added to the Machines folder, because no specification classifies an AutoID device as a machine (OPC 40001-1 11.1 leaves that to the domain specifications), and a reader is a component of a machine only when the application asks for it.

AsComponentOf needs AutoID composed into the Machinery owner (AddMachinery().AddAutoIdModel() or a DI owner that loads the Machinery model) and a machine of that owner that publishes the Components add-in, here built with WithComponents. The runtime finds the add-in through the HasAddIn reference from the machine's MachineryBuildingBlocks folder (OPC 40001-1 7.1). This also finds a container declared by a companion model and bound with WithComponents(existing, ...), regardless of its parent or browse name. Without that folder, the runtime uses the machine's MachineComponentsType child:

IMachineHandle<BaseObjectState>? press = null;
builder
    .ConfigureMachinery(async (machinery, ct) =>
        press = await machinery.AddMachine(new QualifiedName("Press1", machinery.InstanceNamespaceIndex))
            .WithIdentification(id =>
            {
                id.Manufacturer = new LocalizedText("Acme");
                id.SerialNumber = "PR-1";
                id.ProductInstanceUri = "urn:acme:press:1";
            })
            .WithComponents(_ => { })
            .BuildAsync(ct))
    .ConfigureAutoIdFor<MachineryNodeManager>(async (context, ct) =>
        await context.Runtime
            .Reader(new QualifiedName("PressInfeed", context.Runtime.InstanceNamespaceIndex), hardware)
            .AsComponentOf(press!.State)
            .WithIdentification(nameplate =>
            {
                nameplate.Manufacturer = new LocalizedText("Acme");
                nameplate.SerialNumber = "R100-0001";
            })
            .BuildAsync(ct));

The reader gets the 2:Identification add-in typed MachineryComponentIdentificationType. It holds no copies: it references the reader's own DI nameplate properties with HasProperty. This follows the approach of OPC 40001-1 7.3 ("let several References lead to the same Node, rather than duplicating the Node") and of the Robotics example in Annex B.2, whose identification Properties "are only referenced from the Identification functional group". It references Manufacturer, SerialNumber and those of Model, ManufacturerUri, ProductCode, HardwareRevision, SoftwareRevision, DeviceRevision, DeviceClass and ProductInstanceUri that are set, plus AssetId and ComponentName when the reader publishes them; DeviceManual and RevisionCounter are left out as OPC 40001-1 10.2 recommends. A missing Manufacturer or SerialNumber, a machine of another node manager, a machine without Components or with more than one, or a server without the Machinery model fail the build with Bad_ConfigurationError before anything is registered. WithParent and AsComponentOf exclude each other. The runtime does not add Machinery conformance units; the Machinery owner advertises them for what its builders created.

Direct composition and lifetime

Without dependency injection, pass new AutoIdModelProvider() in the provider collection of the four-argument DiNodeManager constructor, or load AutoID from a custom owner's LoadPredefinedNodesAsync with nodes.AddAutoIdTypeSystem(context). Once the address space is created:

AutoIdRuntime autoId = owner.CreateAutoIdRuntime();
AutoIdReader reader = await autoId.CreateReaderAsync(
    new QualifiedName("PressInfeed", autoId.InstanceNamespaceIndex), hardware, ct);

The first CreateAutoIdRuntime(options) call selects the options; later calls return the same runtime, and on an AutoIdNodeManager it returns its Runtime. The stand-alone AutoIdNodeManager is built from the same pieces: a Device Integration owner that loads DI and then AutoIdModelProvider. Any DI owner can call CreateAutoIdRuntime() or use ConfigureAutoIdFor<TOwner>. The runtime registers its lifetime with DiNodeManager.RegisterResource, so the owner disposes it automatically. Custom owners no longer need a Machinery-specific disposal override.

Providers

A reader exposes a hardware provider through OPC UA. The base contract IAutoIdReaderProvider (kind, attach, detach) is enough for a device that scans on its own (OPC 30010 6.1.1 option 3): the provider reports through the IAutoIdReaderSink it receives when attached. Capabilities are added by implementing more interfaces:

Interface	Methods it enables
IAutoIdScanProvider	Scan
IAutoIdAsyncScanProvider	ScanStart, ScanStop
IAutoIdRfidProvider (SupportedOperations)	ReadTag, WriteTag, WriteTagID, KillTag, LockTag, SetTagPassword, each only when listed
IAutoIdRtlsProvider	GetLocation, GetSupportedLocationTypes

The sink pushes ReportScanAsync (scan event and LastScanData), CompleteScanAsync (a termination condition ended the asynchronous scan), ReportPresenceAsync, ReportLogEntryAsync and ReportAccessAsync. Provider calls are made without any runtime lock held, scans never overlap on one reader, and the sink throws ObjectDisposedException after the reader was disposed.

Four simulated providers ship in the package and back the tests and the sample: InMemoryRfidReaderProvider (an EPC Gen2 reader with memory banks, passwords, locks and kill), InMemoryScanReaderProvider (OCR and optical), InMemoryOpticalVerifierProvider and InMemoryRtlsProvider. Their scan cycle defaults to one second (CycleInterval), so an unbounded ScanStart raises at most one scan event per second; pass a cycleInterval to the constructor for another interval. InMemoryRtlsProvider stores each object's location in the type it was registered with. A locationConverter translates it into the other supported types, for example from the configured local coordinate system (OPC 30010 9.3.4) into WGS84:

// A site whose local origin is at 48 N 11 E, X pointing east and Y north, in metres.
var rtls = new InMemoryRtlsProvider(locationConverter: (location, type) =>
    type == LocationTypeEnumeration.WGS84 && location.SwitchField == LocationFields.Local
        ? new Location
        {
            SwitchField = LocationFields.WGS84,
            WGS84 = new WGS84Coordinate
            {
                N_S_Hemisphere = "N",
                Latitude = 48.0 + (location.Local.Y / 111_320.0),
                E_W_Hemisphere = "E",
                Longitude = 11.0 + (location.Local.X / 74_600.0)
            }
        }
        : null);

Without a converter, or when it returns null, GetLocation for another type answers Bad_InvalidState.

Behavior of the methods

Method	Result codes and semantics
Scan (6.1.3.4)	Bad_InvalidArgument for an infinite scan (duration 0, cycles 0, no DataAvailable), a negative or non-finite value, an undefined location type or a duration above the limit; Bad_InvalidState while another scan is active. The first result becomes LastScanData/LastScanTimestamp with one source timestamp
ScanStart (6.1.3.5)	Infinite settings allowed; Bad_InvalidState while a scan is active. The scan stops through ScanStop, when the provider completes it, when the starting session closes, or at shutdown
ScanStop (6.1.3.6)	Bad_InvalidState when no scan is active; any session may stop a scan
ReadTag, WriteTag, WriteTagID, KillTag, LockTag, SetTagPassword	A malformed identifier, empty code type, over-long read or undefined enumeration is Bad_InvalidArgument. Everything the tag decides (PASSWORD_ERROR_4, OUT_OF_RANGE_ERROR_7, ...) is returned in Status with a good call result
GetDeviceLocation (6.1.3.7)	Available when a location is configured. Same mapping as GetLocation: an undefined location type is Bad_InvalidArgument, a location that is not available in the requested type Bad_InvalidState. 6.1.3.7 lists only the Call Service codes of OPC 10000-4 5.12.2, where Bad_NotSupported would mean the method is not supported for the object; 5.12.2.4 allows reusing a code with the same canonical meaning
GetLocation, GetSupportedLocationTypes (6.6.3)	The result carries the location in the requested type. An unsupported location type is Bad_InvalidArgument, an unknown object Bad_NotFound, and a supported type the object's location is not available in Bad_InvalidState (6.6.3.2: not available, for example due to the configuration)

A method the provider does not support is not instantiated; calling it fails with the stack's status for an unpublished method.

Events

Scan results are raised as the scan event of the reader kind (RfidScanEventType, OcrScanEventType, OpticalScanEventType, OpticalVerifierScanEventType, RtlsLocationEventType) with DeviceName and the typed ScanResult array. AutoIdPresenceEventType and AutoIdLogEntryEventType come from the sink. Commands that reached an identifier (a scan with results, and each tag command except those answering NO_IDENTIFIER_8, MULTIPLE_IDENTIFIERS_9, NOT_SUPPORTED_BY_DEVICE_15, DEVICE_NOT_READY_17, INVALID_CONFIGURATION_18 or DEVICE_FAULT_20) raise RfidAccessEventType on RFID readers and AutoIdAccessEventType otherwise, with Client, Command and the access results. Client names the client application that originated the command (OPC 30010 6.1.3.3 and 7.10): the application name of the client description the session was created with, else its application URI, else OPC UA client. The results of an asynchronous scan name the client that called ScanStart; scans the device reports on its own name AutoID device.

Generic ReadTag and WriteTag access events do not automatically broadcast tag memory. The injected RFID provider may also implement IAutoIdRfidAccessEventPolicy to approve an entire (codeType, region, offset, length) byte range as non-secret telemetry. Missing, rejected or failing classifications omit both RWData and CodeTypeRWData, including their encoding-mask bits; identifiers and command metadata remain available. Unsuccessful operations and empty results omit data. EPC Gen2 reserved-bank ranges overlapping password bytes 0 through 7 are always omitted, even if a policy approves them. The in-memory EPC provider approves ordinary banks 1 through 3 and never approves the reserved bank.

This projection does not redact an authorized caller's direct ReadTag result, change provider arguments, or disable access events. Password-management commands never include passwords in their access events. Applications whose existing RFID providers need ordinary memory in events must opt in through this provider policy; only approve known layouts and never credential-bearing or unclassified memory.

Conformance

The runtime contributes the OPC 30010 conformance units and server facets (Tables 82 to 85) of the readers it hosts; a facet is advertised only when a reader implements all its mandatory units.

Unit	Implemented when
AutoID DeviceType	A reader exists
AutoID Simple Sync Access	A reader exists (LastScanData is updated by every scan)
AutoID Sync Access	A reader has a Scan method
AutoID Async Access	A reader exists (scan events)
AutoID Async Access Control	A reader has ScanStart and ScanStop

The Simple Sync, Base Sync and Base Async facets are advertised accordingly. AutoID Simple Sync Access Control (the ScanActive variable and the ScanSettings function group) and AutoID Device Parameters (the RuntimeParameters group) are not implemented, so the Full AutoID Server Facet is never advertised. DeviceInfo, DeviceLocation, DeviceLocationName and AntennaNames are published when configured.

Client

Opc.Ua.AutoID.Client wraps the generated ObjectType proxies:

using Opc.Ua.AutoID.Client;

AutoIdClient autoId = session.AutoId(telemetry);   // or AddAutoIdClient() in DI
await foreach (AutoIdReaderEntry reader in autoId.EnumerateReadersAsync())
{
    AutoIdDeviceSnapshot device = await autoId.ReadDeviceAsync(reader);
    AutoIdScanResponse scan = await autoId.ScanAsync(
        reader, new ScanSettings { Duration = 1000, DataAvailable = true });
}

await foreach (AutoIdScanEventTypeRecord e in
    autoId.ObserveScanEventsAsync(session.DefaultStreaming, reader, ct))
{
    // e.ScanResult holds RfidScanResult, OcrScanResult, ... instances
}

Discovery finds the devices whose type derives from one of the five concrete reader types. A browse the server rejects throws ServiceResultException rather than yielding an empty list, a rejected method call throws with the server's status, and every asynchronous member honours cancellation. The status a device reports for a tag command is returned as data. AutoIdReadOptions limits which variables ReadDeviceAsync reads: Default reads everything the device publishes, StatusOnly reads DeviceStatus and DeviceName. Every ReadDeviceAsync call costs one Browse of the children of the device (and BrowseNext only when the server pages the result) and one Read, whatever the options. The snapshot carries the NodeIds of DeviceStatus, LastScanData, LastScanTimestamp and DeviceLocation and the browse names of the methods the device publishes, taken from that browse. RefreshDeviceAsync takes such a snapshot and reads DeviceStatus, LastScanData, LastScanTimestamp and DeviceLocation again through these NodeIds: one Read of up to four variables and no Browse. The client keeps no state, so a poller reads once and then refreshes the snapshot:

Call	Network cost
ReadDeviceAsync(reader)	One Browse, one Read of every published variable
ReadDeviceAsync(reader, AutoIdReadOptions.StatusOnly)	One Browse, one Read of two variables
RefreshDeviceAsync(snapshot)	One Read of up to four variables, no Browse

AutoIdDeviceSnapshot device = await autoId.ReadDeviceAsync(reader, AutoIdReadOptions.StatusOnly);
if (device.HasMethod(BrowseNames.ScanStart))
{
    // monitor device.DeviceStatusId and device.LastScanDataId, then start the scan
}
device = await autoId.RefreshDeviceAsync(device); // poll without browsing

RefreshDeviceAsync copies every other member of the snapshot, including Methods, and does not check the snapshot against the server. When the snapshot no longer matches the device (the device or one of its variables was deleted, or the server assigned other NodeIds after a restart), the status of the Read surfaces: a bad status for DeviceStatus, for example BadNodeIdUnknown, is thrown as ServiceResultException, and a bad status for LastScanData is returned in LastScanStatus with a null value. The caller then reads the device again with ReadDeviceAsync, which also picks up optional variables and methods published after the snapshot was taken.

Observe*Async methods (scan, access, presence and log entry events) take a streaming subscription the caller owns; the monitored item lives as long as the enumeration.

MCP tools

AddOpcUaMcpAutoId() and WithOpcUaAutoIdTools(McpToolProfile.AutoId) (profile autoid) add autoid_list_readers, autoid_read_device, autoid_scan, autoid_scan_start, autoid_scan_stop, autoid_observe_scan_events, autoid_read_tag, autoid_get_supported_location_types and autoid_get_location. No tool writes, locks or kills a tag or carries a password. See the MCP server guide.

Sample

samples/AutoID contains AutoIdServer, a dock door with a simulated RFID portal whose pallets enter and leave the antenna field, and AutoIdClient, which discovers the reader, scans, reads and writes tag memory and prints the scan and presence events. Test-AutoIdSamplePair.ps1 runs both and checks the output.

Specification notes

• OPC 30010 6.1.3.16 prescribes the AutoIdModelVersion string "1.00" although the released model is 1.01; the server publishes "1.00".
• The NodeSet orders the GetLocation arguments identifier, location type, code type; the specification text orders them identifier, code type, location type. The generated proxy and the server follow the NodeSet.
• The NodeSet declares the Scan method of OpticalVerifierDeviceType with WGS84Coordinate results where OPC 30010 6.4.3.1 names OpticalVerifierScanResult. The method cannot be served consistently, so a verifier does not publish Scan; it reports through ScanStart and scan events, and AutoIdClient.ScanAsync refuses a verifier.
• The GetUnits method of RtlsDeviceType declares no output argument; it is not published.

Provenance

src/Opc.Ua.AutoID/Model holds the unmodified NodeSet and identifier table from UA-Nodeset revision 9f6c7660b94af24d32c4248d4b13bf60adab0301; provenance.json records the source URLs and SHA-256 hashes. The published identifier table predates model 1.01 and lacks 67 NodeSet declarations, so Opc.Ua.AutoID.Derived.NodeIds.csv is generated from it with tools/nodesets/derive-identifier-table.py and used as the source generator's drift guard. NodeIds always come from the NodeSet.

The AutoID tests pin the file hashes, compare the generated identifiers with the NodeSet and the identifier table, load the model with DI, and round-trip the DataTypes through the binary, JSON and XML encodings.

Fixture	Covers
AutoIdHostingTests	AddAutoId registration, DI ownership, options, node manager and client factories
AutoIdCompositionTests	Stock Machinery owner, ordered providers, DI loaded once, instance ownership, rollback, cancellation, runtime disposal, a second DI owner rejected
AutoIdMachineryCompositionEndToEndTests	Machinery, Pumps and AutoID in one hosted server, read back by the AutoID, Machinery and Pumps clients over a real session, with the published profiles and conformance units
AutoIdPlacementEndToEndTests	Reader placement over a real session: every reader reachable from DeviceSet, only roots organized by it, a reader as a component of a machine with its Identification, no reader in Machines
AutoIdReaderEndToEndTests	The stand-alone server driven by AutoIdClient over a real session