Types Reference

Core Types

NodeId

Identifies a node in the OPC UA address space.

use PhpOpcua\Client\Types\NodeId;

$nodeId = NodeId::numeric(0, 85);           // ns=0;i=85
$nodeId = NodeId::string(2, 'Temperature'); // ns=2;s=Temperature
$nodeId = NodeId::guid(1, '550e8400-e29b-41d4-a716-446655440000');
$nodeId = NodeId::opaque(1, 'DEADBEEF');

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $nodeId->namespaceIndex | int | Namespace index | | $nodeId->identifier | int\|string | The node identifier | | $nodeId->type | string | 'numeric', 'string', 'guid', or 'opaque' |

Methods:

| Method | Returns | Description | |---|---|---| | isNumeric() | bool | True if numeric identifier | | isString() | bool | True if string identifier | | isGuid() | bool | True if GUID identifier | | isOpaque() | bool | True if opaque (ByteString) identifier | | getEncodingByte() | int | Binary protocol encoding byte | | __toString() | string | OPC UA string format (e.g. ns=2;i=1001) |

String format in client methods:

All public client methods that accept a NodeId parameter also accept a NodeId|string union type. Strings are parsed automatically using OPC UA notation. Invalid strings throw InvalidNodeIdException.

// These are equivalent:
$client->read(NodeId::numeric(0, 2259));
$client->read('i=2259');

$client->browse(NodeId::numeric(0, 85));
$client->browse('i=85');

$client->write(NodeId::numeric(2, 1001), 42, BuiltinType::Int32);
$client->write('ns=2;i=1001', 42, BuiltinType::Int32);

Parsing and serialization:

$nodeId = NodeId::parse('ns=2;i=1001');
$nodeId = NodeId::parse('i=85');          // ns=0 implied
$nodeId = NodeId::parse('ns=2;s=MyNode');

echo (string) $nodeId; // "ns=2;i=1001"

Variant

Typed value container. Wraps any OPC UA value with its type information.

use PhpOpcua\Client\Types\Variant;
use PhpOpcua\Client\Types\BuiltinType;

$v = new Variant(BuiltinType::Int32, 42);
$v = new Variant(BuiltinType::String, 'Hello');
$v = new Variant(BuiltinType::Double, 3.14);
$v = new Variant(BuiltinType::Boolean, true);
$v = new Variant(BuiltinType::DateTime, new DateTimeImmutable());

// Arrays
$v = new Variant(BuiltinType::Int32, [1, 2, 3, 4, 5]);
$v = new Variant(BuiltinType::String, ['a', 'b', 'c']);

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $v->type | BuiltinType | The OPC UA type | | $v->value | mixed | The actual value (scalar or array) | | $v->dimensions | ?int[] | Multi-dimensional array dimensions, or null |

Methods:

| Method | Returns | Description | |---|---|---| | isMultiDimensional() | bool | True if dimensions has more than one entry |

DataValue

A value with metadata. The inner Variant is private -- use getValue() to unwrap it.

use PhpOpcua\Client\Types\DataValue;

$dv = new DataValue(
    value: new Variant(BuiltinType::Int32, 42),
    statusCode: 0,
    sourceTimestamp: new DateTimeImmutable(),
    serverTimestamp: new DateTimeImmutable(),
);

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $dv->statusCode | int | OPC UA status code | | $dv->sourceTimestamp | ?DateTimeImmutable | When the source produced the value | | $dv->serverTimestamp | ?DateTimeImmutable | When the server received it |

Methods:

| Method | Returns | Description | |---|---|---| | getValue() | mixed | Unwrapped value from the inner Variant | | getVariant() | ?Variant | The full Variant object (when you need type info) | | getEncodingMask() | int | Bitmask for binary encoding |

> Tip: getValue() returns the raw scalar or array directly. If you need to know the OPC UA type, call getVariant() instead and check ->type.

Factory methods:

DataValue provides static factory methods for creating instances with common types. Each returns a DataValue with status Good, no timestamps, and the appropriate Variant inside.

use PhpOpcua\Client\Types\DataValue;
use PhpOpcua\Client\Types\BuiltinType;
use PhpOpcua\Client\Types\StatusCode;

// Typed factories
DataValue::ofInt32(42);
DataValue::ofDouble(3.14);
DataValue::ofString('Hello');
DataValue::ofBoolean(true);
DataValue::ofFloat(1.5);
DataValue::ofUInt32(100);
DataValue::ofInt16(7);
DataValue::ofUInt16(8);
DataValue::ofInt64(123456789);
DataValue::ofUInt64(987654321);
DataValue::ofDateTime(new DateTimeImmutable());

// Generic factory ? any BuiltinType
DataValue::of(42, BuiltinType::Int32);

// Bad status (no value)
DataValue::bad(StatusCode::BadNodeIdUnknown);

| Factory Method | Type | Description | |---|---|---| | ofInt32(int $v) | BuiltinType::Int32 | Signed 32-bit integer | | ofDouble(float $v) | BuiltinType::Double | 64-bit float | | ofString(string $v) | BuiltinType::String | UTF-8 string | | ofBoolean(bool $v) | BuiltinType::Boolean | Boolean | | ofFloat(float $v) | BuiltinType::Float | 32-bit float | | ofUInt32(int $v) | BuiltinType::UInt32 | Unsigned 32-bit integer | | ofInt16(int $v) | BuiltinType::Int16 | Signed 16-bit integer | | ofUInt16(int $v) | BuiltinType::UInt16 | Unsigned 16-bit integer | | ofInt64(int $v) | BuiltinType::Int64 | Signed 64-bit integer | | ofUInt64(int $v) | BuiltinType::UInt64 | Unsigned 64-bit integer | | ofDateTime(DateTimeImmutable $v) | BuiltinType::DateTime | Date/time | | of(mixed $v, BuiltinType $type) | any | Generic factory for any built-in type | | bad(int $statusCode) | N/A | DataValue with no value and a bad status code |

BuiltinType (Enum)

All 25 OPC UA built-in data types:

use PhpOpcua\Client\Types\BuiltinType;

| Case | Value | | Case | Value | |---|---|---|---|---| | Boolean | 1 | | DateTime | 13 | | SByte | 2 | | Guid | 14 | | Byte | 3 | | ByteString | 15 | | Int16 | 4 | | XmlElement | 16 | | UInt16 | 5 | | NodeId | 17 | | Int32 | 6 | | ExpandedNodeId | 18 | | UInt32 | 7 | | StatusCode | 19 | | Int64 | 8 | | QualifiedName | 20 | | UInt64 | 9 | | LocalizedText | 21 | | Float | 10 | | ExtensionObject | 22 | | Double | 11 | | DataValue | 23 | | String | 12 | | Variant / DiagnosticInfo | 24 / 25 |

Value Types

QualifiedName

A name qualified by a namespace index.

use PhpOpcua\Client\Types\QualifiedName;

$qn = new QualifiedName(0, 'ServerStatus');

Properties (public readonly):

| Property | Type | |---|---| | $qn->namespaceIndex | int | | $qn->name | string |

__toString() returns 'ServerStatus' for ns=0, or '2:Temperature' for ns=2.

LocalizedText

A string with an optional locale.

use PhpOpcua\Client\Types\LocalizedText;

$lt = new LocalizedText('en', 'Server Status');

Properties (public readonly):

| Property | Type | |---|---| | $lt->locale | string | | $lt->text | string |

__toString() returns the text.

StatusCode

Utility class for OPC UA status codes. All methods are static.

use PhpOpcua\Client\Types\StatusCode;

StatusCode::isGood(0x00000000);      // true
StatusCode::isBad(0x80340000);       // true
StatusCode::isUncertain(0x408F0000); // true
StatusCode::getName(0x80340000);     // 'BadNodeIdUnknown'

Static methods:

| Method | Returns | Description | |---|---|---| | isGood(int $code) | bool | Top 2 bits are 00 | | isBad(int $code) | bool | Top 2 bits are 10 | | isUncertain(int $code) | bool | Top 2 bits are 01 | | getName(int $code) | string | Human-readable name, or hex fallback |

Constants:

| Constant | Value | |---|---| | StatusCode::Good | 0x00000000 | | StatusCode::BadUnexpectedError | 0x80010000 | | StatusCode::BadInternalError | 0x80020000 | | StatusCode::BadOutOfMemory | 0x80030000 | | StatusCode::BadCommunicationError | 0x80050000 | | StatusCode::BadTimeout | 0x800A0000 | | StatusCode::BadServiceUnsupported | 0x800B0000 | | StatusCode::BadNothingToDo | 0x800F0000 | | StatusCode::BadTooManyOperations | 0x80100000 | | StatusCode::BadUserAccessDenied | 0x801F0000 | | StatusCode::BadSecureChannelIdInvalid | 0x80220000 | | StatusCode::BadSessionIdInvalid | 0x80250000 | | StatusCode::BadNodeIdUnknown | 0x80340000 | | StatusCode::BadAttributeIdInvalid | 0x80350000 | | StatusCode::BadIndexRangeInvalid | 0x80360000 | | StatusCode::BadNotWritable | 0x803B0000 | | StatusCode::BadNotReadable | 0x803E0000 | | StatusCode::BadTypeMismatch | 0x80740000 | | StatusCode::BadMethodInvalid | 0x80750000 | | StatusCode::BadArgumentsMissing | 0x80760000 | | StatusCode::BadInvalidArgument | 0x80AB0000 | | StatusCode::BadNoData | 0x80B10000 | | StatusCode::UncertainNoCommunicationLastUsableValue | 0x408F0000 |

Browse Types

ReferenceDescription

A reference between nodes, returned by browse().

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $ref->referenceTypeId | NodeId | Type of reference | | $ref->isForward | bool | Direction of the reference | | $ref->nodeId | NodeId | Target node | | $ref->browseName | QualifiedName | Browse name of the target | | $ref->displayName | LocalizedText | Display name of the target | | $ref->nodeClass | NodeClass | Node class of the target | | $ref->typeDefinition | ?NodeId | Type definition, if available |

BrowseNode

Tree node from browseRecursive(). Wraps a ReferenceDescription with children.

Properties (public readonly):

| Property | Type | |---|---| | $node->reference | ReferenceDescription |

Access the underlying reference data through $node->reference->nodeId, $node->reference->displayName, etc.

Methods:

| Method | Returns | Description | |---|---|---| | getChildren() | BrowseNode[] | Child nodes | | hasChildren() | bool | True if this node has children | | addChild(BrowseNode $child) | void | Add a child node |

See Browsing for tree traversal examples.

BrowseDirection (Enum)

use PhpOpcua\Client\Types\BrowseDirection;

| Case | Value | Description | |---|---|---| | Forward | 0 | Browse children | | Inverse | 1 | Browse parents | | Both | 2 | Browse both directions |

NodeClass (Enum)

use PhpOpcua\Client\Types\NodeClass;

| Case | Value | |---|---| | Unspecified | 0 | | Object | 1 | | Variable | 2 | | Method | 4 | | ObjectType | 8 | | VariableType | 16 | | ReferenceType | 32 | | DataType | 64 | | View | 128 |

Server Types

EndpointDescription

Server endpoint info, returned by getEndpoints().

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $ep->endpointUrl | string | Endpoint URL | | $ep->serverCertificate | ?string | DER-encoded certificate | | $ep->securityMode | int | 1 = None, 2 = Sign, 3 = SignAndEncrypt | | $ep->securityPolicyUri | string | Security policy URI | | $ep->userIdentityTokens | UserTokenPolicy[] | Supported auth methods | | $ep->transportProfileUri | string | Transport profile URI | | $ep->securityLevel | int | Relative security ranking |

UserTokenPolicy

Authentication method supported by an endpoint.

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $policy->policyId | ?string | Policy identifier | | $policy->tokenType | int | 0 = Anonymous, 1 = Username, 2 = Certificate | | $policy->issuedTokenType | ?string | Issued token type URI | | $policy->issuerEndpointUrl | ?string | Issuer endpoint URL | | $policy->securityPolicyUri | ?string | Security policy for this token |

ConnectionState (Enum)

use PhpOpcua\Client\Types\ConnectionState;

| Case | Description | |---|---| | Disconnected | Never connected, or cleanly disconnected | | Connected | Active connection | | Broken | Connection was lost |

Used by $client->getConnectionState() and $client->isConnected(). See Connection & Configuration.

AttributeId

Constants for OPC UA node attributes.

use PhpOpcua\Client\Types\AttributeId;

| Constant | Value | | Constant | Value | |---|---|---|---|---| | NodeId | 1 | | EventNotifier | 12 | | NodeClass | 2 | | Value | 13 | | BrowseName | 3 | | DataType | 14 | | DisplayName | 4 | | ValueRank | 15 | | Description | 5 | | ArrayDimensions | 16 | | WriteMask | 6 | | AccessLevel | 17 | | UserWriteMask | 7 | | UserAccessLevel | 18 | | IsAbstract | 8 | | MinimumSamplingInterval | 19 | | Symmetric | 9 | | Historizing | 20 | | InverseName | 10 | | Executable | 21 | | ContainsNoLoops | 11 | | UserExecutable | 22 |

> Note: AttributeId::Value (13) is the default for read() and write().

Result DTOs

All result DTOs use public readonly properties.

> v5.0.0 Note: Module-specific DTOs have moved from Types\ to their module's namespace. Shared types (NodeId, DataValue, Variant, StatusCode, etc.) remain in Types\. Update your use imports accordingly: > > | Class | Old Location | New Location | > |---|---|---| > | CallResult | PhpOpcua\Client\Types\CallResult | PhpOpcua\Client\Module\ReadWrite\CallResult | > | BrowseResultSet | PhpOpcua\Client\Types\BrowseResultSet | PhpOpcua\Client\Module\Browse\BrowseResultSet | > | BrowsePathResult | PhpOpcua\Client\Types\BrowsePathResult | PhpOpcua\Client\Module\TranslateBrowsePath\BrowsePathResult | > | SubscriptionResult | PhpOpcua\Client\Types\SubscriptionResult | PhpOpcua\Client\Module\Subscription\SubscriptionResult | > | MonitoredItemResult | PhpOpcua\Client\Types\MonitoredItemResult | PhpOpcua\Client\Module\Subscription\MonitoredItemResult | > | PublishResult | PhpOpcua\Client\Types\PublishResult | PhpOpcua\Client\Module\Subscription\PublishResult | > | TransferResult | PhpOpcua\Client\Types\TransferResult | PhpOpcua\Client\Module\Subscription\TransferResult | > | AddNodesResult | PhpOpcua\Client\Types\AddNodesResult | PhpOpcua\Client\Module\NodeManagement\AddNodesResult | > | BuildInfo | PhpOpcua\Client\Types\BuildInfo | PhpOpcua\Client\Module\ServerInfo\BuildInfo |

BrowseResultSet

Returned by browseWithContinuation() and browseNext().

| Property | Type | Description | |---|---|---| | $result->references | ReferenceDescription[] | Browse results | | $result->continuationPoint | ?string | null when there are no more results |

See Browsing.

BrowsePathResult

Returned by translateBrowsePaths(), one per path.

| Property | Type | Description | |---|---|---| | $result->statusCode | int | Status of the path resolution | | $result->targets | BrowsePathTarget[] | Resolved targets |

BrowsePathTarget

A single target resolved from a browse path.

| Property | Type | Description | |---|---|---| | $target->targetId | NodeId | The resolved NodeId | | $target->remainingPathIndex | int | 0xFFFFFFFF if fully resolved |

CallResult

Returned by call(). See Method Calling.

| Property | Type | Description | |---|---|---| | $result->statusCode | int | Method execution status | | $result->inputArgumentResults | int[] | Per-argument validation status codes | | $result->outputArguments | Variant[] | Output values |

SubscriptionResult

Returned by createSubscription(). See Subscriptions.

| Property | Type | Description | |---|---|---| | $result->subscriptionId | int | Server-assigned subscription ID | | $result->revisedPublishingInterval | float | Actual interval in ms | | $result->revisedLifetimeCount | int | Actual lifetime count | | $result->revisedMaxKeepAliveCount | int | Actual keep-alive count |

MonitoredItemResult

Returned per item by createMonitoredItems() and createEventMonitoredItem(). See Subscriptions.

| Property | Type | Description | |---|---|---| | $result->monitoredItemId | int | Server-assigned item ID | | $result->statusCode | int | Creation status | | $result->revisedSamplingInterval | float | Actual sampling interval in ms | | $result->revisedQueueSize | int | Actual queue size |

PublishResult

Returned by publish(). See Subscriptions.

| Property | Type | Description | |---|---|---| | $result->subscriptionId | int | Which subscription this belongs to | | $result->sequenceNumber | int | Sequence number (for acknowledgment) | | $result->moreNotifications | bool | True if more notifications are waiting | | $result->notifications | array | Notification entries |

Each entry in notifications is an associative array. For data changes: type, clientHandle, dataValue. For events: type, clientHandle, eventFields.

TransferResult

Returned per subscription by transferSubscriptions(). See Subscriptions.

| Property | Type | Description | |---|---|---| | $result->statusCode | int | Transfer status for this subscription | | $result->availableSequenceNumbers | int[] | Sequence numbers available for republishing |

AddNodesResult

Returned per node by addNodes(). See Node Management.

use PhpOpcua\Client\Types\AddNodesResult;

| Property | Type | Description | |---|---|---| | $result->statusCode | int | OPC UA status code for this node creation | | $result->addedNodeId | NodeId | The server-assigned NodeId of the new node |

BuildInfo

Returned by getServerBuildInfo(). Contains metadata about the connected server's software.

use PhpOpcua\Client\Types\BuildInfo;

| Property | Type | Description | |---|---|---| | $info->productName | ?string | Server product name (ns=0;i=2262) | | $info->manufacturerName | ?string | Server manufacturer (ns=0;i=2263) | | $info->softwareVersion | ?string | Software version string (ns=0;i=2264) | | $info->buildNumber | ?string | Build number (ns=0;i=2265) | | $info->buildDate | ?DateTimeImmutable | Build date (ns=0;i=2266) |

Type Discovery

StructureField

Describes a single field within a structure definition. Returned as part of StructureDefinition.

use PhpOpcua\Client\Types\StructureField;

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $field->name | string | Field name | | $field->dataType | NodeId | OPC UA data type of the field | | $field->valueRank | int | -1 = scalar, 1 = array | | $field->builtinType | BuiltinType | Resolved built-in type for encoding | | $field->isOptional | bool | Whether the field is optional |

StructureDefinition

Describes the layout of a custom structure type. Used by discoverDataTypes() to build dynamic codecs.

use PhpOpcua\Client\Types\StructureDefinition;

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $def->defaultEncodingId | NodeId | Binary encoding NodeId | | $def->baseDataType | NodeId | Base data type NodeId | | $def->structureType | int | 0 = Structure, 1 = StructureWithOptionalFields, 2 = Union | | $def->fields | StructureField[] | Ordered list of fields |

ExtensionObject

Represents an OPC UA ExtensionObject ? a typed container for custom binary or XML structures.

use PhpOpcua\Client\Types\ExtensionObject;

Properties (public readonly):

| Property | Type | Description | |---|---|---| | $ext->typeId | NodeId | Encoding NodeId identifying the type | | $ext->encoding | int | 0x01 = binary, 0x02 = XML, 0x00 = no body | | $ext->body | ?string | Raw body bytes. Null when decoded via codec. | | $ext->value | mixed | Decoded value from codec. Null when raw. |

Methods:

| Method | Returns | Description | |---|---|---| | isDecoded() | bool | True if decoded by a registered codec | | isRaw() | bool | True if no codec was available (raw body) |

Behavior with DataValue::getValue():

• With codec registered: `getValue()` auto-extracts `$ext->value` ? returns the decoded data directly (e.g. `['x' => 1.0, 'y' => 2.0]`)
• Without codec: `getValue()` returns the `ExtensionObject` DTO ? access `->typeId`, `->body`, etc.

$value = $client->read($pointNodeId)->getValue();

if ($value instanceof ExtensionObject) {
    echo $value->typeId;   // raw, no codec
    echo $value->body;     // binary blob
} else {
    echo $value['x'];      // decoded via codec
}

ExtensionObject Codecs

Register codecs to automatically decode ExtensionObjects. Full guide: ExtensionObject Codecs.

$repo = new ExtensionObjectRepository();
$repo->register(NodeId::numeric(2, 5001), MyPointCodec::class);

$client = ClientBuilder::create($repo)
    ->connect('opc.tcp://localhost:4840');

$result = $client->read($pointNodeId);
// $result->getValue() => ['x' => 1.0, 'y' => 2.0, 'z' => 3.0]

Each Client has its own isolated repository. If you do not pass one, the builder creates an empty one internally.