DataTypeDescription Property (_UADataTypeDescriptor)

Identification of the data type inside the data type dictionary.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<CanBeNullAttribute()>
Property DataTypeDescription As Object

'Usage
 
Dim instance As _UADataTypeDescriptor
Dim value As Object
 
instance.DataTypeDescription = value
 
value = instance.DataTypeDescription

[CanBeNull()]
object DataTypeDescription {get; set;}

[CanBeNull()]
property Object^ DataTypeDescription {
   Object^ get();
   void set (    Object^ value);
}

Remarks

Notice the terminology: The data type *description* is a part of the data type *descriptor*.

OPC UA Part 3: "A DataTypeDescription provides the information necessary to find the formal description of a DataType within the DataTypeDictionary. The Value of a DataTypeDescription depends on the DataTypeSystem of the DataTypeDictionary. When using “OPC Binary” dictionaries the Value shall be the name of the TypeDescription. When using “XML Schema” dictionaries the Value shall be an Xpath expression (see XPATH) which points to an XML element in the schema document."

Example

.NET

// Shows how to obtain data type description object for complex data node with OPC UA Complex Data plug-in, and the actual
// content of the data type dictionary.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

using System;
using System.Text;
using Microsoft.Extensions.DependencyInjection;
using OpcLabs.BaseLib.OperationModel.Generic;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
using OpcLabs.EasyOpc.UA.DataTypeModel;
using OpcLabs.EasyOpc.UA.DataTypeModel.Extensions;
using OpcLabs.EasyOpc.UA.InformationModel;
using OpcLabs.EasyOpc.UA.Plugins.ComplexData;

namespace UADocExamples.ComplexData._IUADataTypeDictionaryProvider
{
    class ResolveDataTypeDescriptorFromDataTypeEncodingId
    {
        public static void Main1()
        {
            // Define which server we will work with.
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            // Instantiate the client object.
            var client = new EasyUAClient();

            // Obtain the data type ID.
            //
            // In many cases, you would be able to obtain the data type ID of a particular node by reading its DataType
            // attribute, or easier, by calling the extension method ReadDataType on the IEasyUAClient interface. The sample
            // server, however, shows a more advanced approach in which the data type ID refers to an abstract data type,
            // and the actual values are then sub-types of this base data type. This abstract data type does not have any
            // encodings associated with it and it is therefore not possible to extract its description from the server.
            // We therefore use a hard-coded data type ID for one of the sub-types in this example.
            //
            // The code to obtain the data type ID for given node would normally look like this:
            //    UANodeId dataTypeId = client.ReadDataType(
            //        endpointUriString,
            //        "nsu=http://test.org/UA/Data/ ;i=10239");    // [ObjectsFolder]/Data.Static.Scalar.StructureValue
            //
            UANodeId dataTypeId = "nsu=http://test.org/UA/Data/ ;i=9440";    // ScalarValueDataType

            // Get the IEasyUAClientComplexData service from the client. This is needed for advanced complex data 
            // operations.
            IEasyUAClientComplexData complexData = client.GetService<IEasyUAClientComplexData>();

            // Get the data type model provider. Provides methods to access data types in OPC UA model.
            IUADataTypeModelProvider dataTypeModelProvider = complexData.DataTypeModelProvider;

            // Resolve the data type ID from our data type ID, for encoding name "Default Binary".
            ValueResult<UAModelNodeDescriptor> encodingIdResult = dataTypeModelProvider.ResolveEncodingIdFromDataTypeId(
                new UAModelNodeDescriptor(endpointDescriptor, dataTypeId),
                UABrowseNames.DefaultBinary);
            // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            if (!encodingIdResult.Succeeded)
            {
                Console.WriteLine("*** Failure: {0}", encodingIdResult.ErrorMessageBrief);
                return;
            }
            UAModelNodeDescriptor encodingId = encodingIdResult.Value;

            // Get the data type dictionary provider. Provides methods to access data type dictionaries in OPC UA model.
            IUADataTypeDictionaryProvider dataTypeDictionaryProvider = complexData.DataTypeDictionaryProvider;

            // Resolve the data type descriptor from the encoding ID.
            ValueResult<UADataTypeDescriptor> dataTypeDescriptorResult =
                dataTypeDictionaryProvider.ResolveDataTypeDescriptorFromDataTypeEncodingId(encodingId);
            // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            if (!dataTypeDescriptorResult.Succeeded)
            {
                Console.WriteLine("*** Failure: {0}", dataTypeDescriptorResult.ErrorMessageBrief);
                return;
            }
            UADataTypeDescriptor dataTypeDescriptor = dataTypeDescriptorResult.Value;

            // The data type descriptor contains two pieces of information:
            // The data type dictionary ID: This determines the dictionary where the data type is defined.
            Console.WriteLine(dataTypeDescriptor.DataTypeDictionaryId);
            // And the data type description: It is a "pointer" into the data type dictionary itself, selecting a specific 
            // type definition inside the data type dictionary. The format of it depends on the data type system;
            // in our case, it is a string that is the name of one of the type elements in the XML document of the data type
            // dictionary.
            Console.WriteLine(dataTypeDescriptor.DataTypeDescription);

            // Obtain the actual content of the data type dictionary.
            ValueResult<byte[]> dataTypeDictionaryResult =
                dataTypeDictionaryProvider.GetDataTypeDictionaryFromDataTypeDictionaryId(dataTypeDescriptor.DataTypeDictionaryId);
            // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            if (!dataTypeDictionaryResult.Succeeded)
            {
                Console.WriteLine("*** Failure: {0}", dataTypeDictionaryResult.ErrorMessageBrief);
                return;
            }
            byte[] dataTypeDictionary = dataTypeDictionaryResult.Value;

            // The data type dictionary returned is an array of bytes; its syntax and semantics depends on the data type 
            // system. In our case, we know that the data type dictionary is actually a string encoded in UTF-8.
            string text = Encoding.UTF8.GetString(dataTypeDictionary);
            Console.WriteLine();
            Console.WriteLine(text);


            // Example output (truncated):
            //
            //http://opcua.demo-this.com:51211/UA/SampleServer; NodeId="nsu=http://test.org/UA/Data/ ;ns=2;i=11422"
            //ScalarValueDataType
            //
            //<opc:TypeDictionary
            //  xmlns:opc="http://opcfoundation.org/BinarySchema/"
            //  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            //  xmlns:ua="http://opcfoundation.org/UA/"
            //  xmlns:tns="http://test.org/UA/Data/"
            //  DefaultByteOrder="LittleEndian"
            //  TargetNamespace="http://test.org/UA/Data/"
            //>
            //  <!-- This File was generated on 2013-01-22 and supports the specifications supported by version 1.1.334.0 of the OPC UA deliverables. -->
            //  <opc:Import Namespace="http://opcfoundation.org/UA/" Location="Opc.Ua.BinarySchema.bsd"/>
            //
            //  <opc:StructuredType Name="ScalarValueDataType" BaseType="ua:ExtensionObject">
            //    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" />
            //    <opc:Field Name="SByteValue" TypeName="opc:SByte" />
            //    <opc:Field Name="ByteValue" TypeName="opc:Byte" />
            //    <opc:Field Name="Int16Value" TypeName="opc:Int16" />
            //    <opc:Field Name="UInt16Value" TypeName="opc:UInt16" />
            //    <opc:Field Name="Int32Value" TypeName="opc:Int32" />
            //    <opc:Field Name="UInt32Value" TypeName="opc:UInt32" />
            //    <opc:Field Name="Int64Value" TypeName="opc:Int64" />
            //    <opc:Field Name="UInt64Value" TypeName="opc:UInt64" />
            //    <opc:Field Name="FloatValue" TypeName="opc:Float" />
            //    <opc:Field Name="DoubleValue" TypeName="opc:Double" />
            //    <opc:Field Name="StringValue" TypeName="opc:String" />
            //    <opc:Field Name="DateTimeValue" TypeName="opc:DateTime" />
            //    <opc:Field Name="GuidValue" TypeName="opc:Guid" />
            //    <opc:Field Name="ByteStringValue" TypeName="opc:ByteString" />
            //    <opc:Field Name="XmlElementValue" TypeName="ua:XmlElement" />
            //    <opc:Field Name="NodeIdValue" TypeName="ua:NodeId" />
            //    <opc:Field Name="ExpandedNodeIdValue" TypeName="ua:ExpandedNodeId" />
            //    <opc:Field Name="QualifiedNameValue" TypeName="ua:QualifiedName" />
            //    <opc:Field Name="LocalizedTextValue" TypeName="ua:LocalizedText" />
            //    <opc:Field Name="StatusCodeValue" TypeName="ua:StatusCode" />
            //    <opc:Field Name="VariantValue" TypeName="ua:Variant" />
            //    <opc:Field Name="EnumerationValue" TypeName="ua:Int32" />
            //    <opc:Field Name="StructureValue" TypeName="ua:ExtensionObject" />
            //    <opc:Field Name="Number" TypeName="ua:Variant" />
            //    <opc:Field Name="Integer" TypeName="ua:Variant" />
            //    <opc:Field Name="UInteger" TypeName="ua:Variant" />
            //  </opc:StructuredType>
            //
            //  <opc:StructuredType Name="ArrayValueDataType" BaseType="ua:ExtensionObject">
            //    <opc:Field Name="NoOfBooleanValue" TypeName="opc:Int32" />
            //    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" LengthField="NoOfBooleanValue" />
            //    <opc:Field Name="NoOfSByteValue" TypeName="opc:Int32" />
        }
    }
}

# Shows how to obtain data type description object for complex data node with OPC UA Complex Data plug-in, and the
# actual content of the data type dictionary.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from Microsoft.Extensions.DependencyInjection import *
from System import *
from System.Text import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.AddressSpace import *
from OpcLabs.EasyOpc.UA.AddressSpace.Standard import *
from OpcLabs.EasyOpc.UA.DataTypeModel.Extensions import *
#from OpcLabs.EasyOpc.UA.Extensions import *
from OpcLabs.EasyOpc.UA.InformationModel import *
from OpcLabs.EasyOpc.UA.Plugins.ComplexData import *


endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# Instantiate the client object.
client = EasyUAClient()

# Obtain the data type ID.
#
# In many cases, you would be able to obtain the data type ID of a particular node by reading its DataType
# attribute, or easier, by calling the extension method ReadDataType on the IEasyUAClient interface.
# The sample server, however, shows a more advanced approach in which the data type ID refers to an abstract
# data type, and the actual values are then sub-types of this base data type. This abstract data type does not
# have any encodings associated with it and it is therefore not possible to extract its description from the
# server. We therefore use a hard-coded data type ID for one of the sub-types in this example.
#
# The code to obtain the data type ID for given node would normally look like this:
#    dataTypeId = IEasyUAClientExtension2.ReadDataType(client,
#        endpointDescriptor,
#        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10239'))    # [ObjectsFolder]/Data.Static.Scalar.StructureValue
dataTypeId = UANodeId('nsu=http://test.org/UA/Data/ ;i=9440')   # ScalarValueDataType

# Get the IEasyUAClientComplexData service from the client. This is needed for advanced complex data
# operations.
complexData = ServiceProviderServiceExtensions.GetService[IEasyUAClientComplexData](client)
if complexData is None:
    print('The client complex data service is not available.')
    exit()

# Get the data type model provider. Provides methods to access data types in OPC UA model.
dataTypeModelProvider = complexData.DataTypeModelProvider

# Resolve the data type ID from our data type ID, for encoding name "Default Binary".
encodingIdResult = IUADataTypeModelProviderExtension.ResolveEncodingIdFromDataTypeId(dataTypeModelProvider,
    UAModelNodeDescriptor(endpointDescriptor, UANodeDescriptor(dataTypeId)),
    UABrowseNames.DefaultBinary)
# Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
if not encodingIdResult.Succeeded:
    print('*** Failure: ', encodingIdResult.ErrorMessageBrief)
    exit()
encodingId = encodingIdResult.Value

# Get the data type dictionary provider. Provides methods to access data type dictionaries in OPC UA model.
dataTypeDictionaryProvider = complexData.DataTypeDictionaryProvider

# Resolve the data type descriptor from the encoding ID.
dataTypeDescriptorResult = IUADataTypeDictionaryProviderExtension.ResolveDataTypeDescriptorFromDataTypeEncodingId(
    dataTypeDictionaryProvider, encodingId)
# Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
if not dataTypeDescriptorResult.Succeeded:
    print('*** Failure: ', dataTypeDescriptorResult.ErrorMessageBrief)
    exit()
dataTypeDescriptor = dataTypeDescriptorResult.Value

# The data type descriptor contains two pieces of information:
# The data type dictionary ID: This determines the dictionary where the data type is defined.
print(dataTypeDescriptor.DataTypeDictionaryId)
# And the data type description: It is a "pointer" into the data type dictionary itself, selecting a specific
# type definition inside the data type dictionary. The format of it depends on the data type system;
# in our case, it is a string that is the name of one of the type elements in the XML document of the data type
# dictionary.
print(dataTypeDescriptor.DataTypeDescription)

# Obtain the actual content of the data type dictionary.
dataTypeDictionaryResult = IUADataTypeDictionaryProviderExtension.GetDataTypeDictionaryFromDataTypeDictionaryId(
    dataTypeDictionaryProvider, dataTypeDescriptor.DataTypeDictionaryId)
# Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
if not dataTypeDictionaryResult.Succeeded:
    print('*** Failure: ', dataTypeDictionaryResult.ErrorMessageBrief)
    exit()
dataTypeDictionary = dataTypeDictionaryResult.Value

# The data type dictionary returned is an array of bytes; its syntax and semantics depends on the data type
# system. In our case, we know that the data type dictionary is actually a string encoded in UTF-8.
text = Encoding.UTF8.GetString(dataTypeDictionary)
print()
print(text)

print()
print('Finished.')

' Shows how to obtain data type description object for complex data node with OPC UA Complex Data plug-in, and the actual
' content of the data type dictionary.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports System
Imports System.Text
Imports Microsoft.Extensions.DependencyInjection
Imports OpcLabs.BaseLib.OperationModel.Generic
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.DataTypeModel
Imports OpcLabs.EasyOpc.UA.DataTypeModel.Extensions
Imports OpcLabs.EasyOpc.UA.InformationModel
Imports OpcLabs.EasyOpc.UA.Plugins.ComplexData

Namespace ComplexData._IUADataTypeDictionaryProvider

    Friend Class ResolveDataTypeDescriptorFromDataTypeEncodingId

        Public Shared Sub Main1()

            ' Define which server we will work with.
            Dim endpointDescriptor As UAEndpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            ' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            ' or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            ' Instantiate the client object.
            Dim client = New EasyUAClient

            ' Obtain the data type ID.
            '
            ' In many cases, you would be able to obtain the data type ID of a particular node by reading its DataType
            ' attribute, or easier, by calling the extension method ReadDataType on the IEasyUAClient interface. The sample
            ' server, however, shows a more advanced approach in which the data type ID refers to an abstract data type,
            ' and the actual values are then sub-types of this base data type. This abstract data type does not have any
            ' encodings associated with it and it is therefore not possible to extract its description from the server.
            ' We therefore use a hard-coded data type ID for one of the sub-types in this example.
            '
            ' The code to obtain the data type ID for given node would normally look like this:
            '    UANodeId dataTypeId = client.ReadDataType(
            '        endpointUriString,
            '        "nsu=http://test.org/UA/Data/ ;i=10239");    // [ObjectsFolder]/Data.Static.Scalar.StructureValue
            '
            Dim dataTypeId As UANodeId = "nsu=http://test.org/UA/Data/ ;i=9440"  ' ScalarValueDataType

            ' Get the IEasyUAClientComplexData service from the client. This is needed for advanced complex data 
            ' operations.
            Dim complexData As IEasyUAClientComplexData = client.GetService(Of IEasyUAClientComplexData)

            ' Get the data type model provider. Provides methods to access data types in OPC UA model.
            Dim dataTypeModelProvider As IUADataTypeModelProvider = complexData.DataTypeModelProvider

            ' Resolve the data type ID from our data type ID, for encoding name "Default Binary".
            Dim encodingIdResult As ValueResult(Of UAModelNodeDescriptor) = dataTypeModelProvider.ResolveEncodingIdFromDataTypeId(
                New UAModelNodeDescriptor(endpointDescriptor, dataTypeId),
                UABrowseNames.DefaultBinary)
            ' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            If Not encodingIdResult.Succeeded Then
                Console.WriteLine("*** Failure: {0}", encodingIdResult.ErrorMessageBrief)
                Exit Sub
            End If
            Dim encodingId As UAModelNodeDescriptor = encodingIdResult.Value

            ' Get the data type dictionary provider. Provides methods to access data type dictionaries in OPC UA model.
            Dim dataTypeDictionaryProvider As IUADataTypeDictionaryProvider = complexData.DataTypeDictionaryProvider

            ' Resolve the data type descriptor from the encoding ID.
            Dim dataTypeDescriptorResult As ValueResult(Of UADataTypeDescriptor) =
                    dataTypeDictionaryProvider.ResolveDataTypeDescriptorFromDataTypeEncodingId(encodingId)
            ' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            If Not dataTypeDescriptorResult.Succeeded Then
                Console.WriteLine("*** Failure: {0}", dataTypeDescriptorResult.ErrorMessageBrief)
                Exit Sub
            End If
            Dim dataTypeDescriptor As UADataTypeDescriptor = dataTypeDescriptorResult.Value

            ' The data type descriptor contains two pieces of information:
            ' The data type dictionary ID: This determines the dictionary where the data type is defined.
            Console.WriteLine(dataTypeDescriptor.DataTypeDictionaryId)
            ' And the data type description: It is a "pointer" into the data type dictionary itself, selecting a specific 
            ' type definition inside the data type dictionary. The format of it depends on the data type system;
            ' in our case, it is a string that is the name of one of the type elements in the XML document of the data type
            ' dictionary.
            Console.WriteLine(dataTypeDescriptor.DataTypeDescription)

            ' Obtain the actual content of the data type dictionary.
            Dim dataTypeDictionaryResult As ValueResult(Of Byte()) =
                    dataTypeDictionaryProvider.GetDataTypeDictionaryFromDataTypeDictionaryId(dataTypeDescriptor.DataTypeDictionaryId)
            ' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
            If Not dataTypeDictionaryResult.Succeeded Then
                Console.WriteLine("*** Failure: {0}", dataTypeDictionaryResult.ErrorMessageBrief)
                Exit Sub
            End If
            Dim dataTypeDictionary() As Byte = dataTypeDictionaryResult.Value

            ' The data type dictionary returned is an array of bytes; its syntax and semantics depends on the data type 
            ' system. In our case, we know that the data type dictionary is actually a string encoded in UTF-8.
            Dim text As String = Encoding.UTF8.GetString(dataTypeDictionary)
            Console.WriteLine()
            Console.WriteLine(text)


            ' Example output (truncated):
            '
            'http://opcua.demo-this.com:51211/UA/SampleServer; NodeId="nsu=http://test.org/UA/Data/ ;ns=2;i=11422"
            'ScalarValueDataType
            '
            '<opc:TypeDictionary
            '  xmlns:opc="http://opcfoundation.org/BinarySchema/"
            '  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            '  xmlns:ua="http://opcfoundation.org/UA/"
            '  xmlns:tns="http://test.org/UA/Data/"
            '  DefaultByteOrder="LittleEndian"
            '  TargetNamespace="http://test.org/UA/Data/"
            '>
            '  <!-- This File was generated on 2013-01-22 and supports the specifications supported by version 1.1.334.0 of the OPC UA deliverables. -->
            '  <opc:Import Namespace="http://opcfoundation.org/UA/" Location="Opc.Ua.BinarySchema.bsd"/>
            '
            '  <opc:StructuredType Name="ScalarValueDataType" BaseType="ua:ExtensionObject">
            '    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" />
            '    <opc:Field Name="SByteValue" TypeName="opc:SByte" />
            '    <opc:Field Name="ByteValue" TypeName="opc:Byte" />
            '    <opc:Field Name="Int16Value" TypeName="opc:Int16" />
            '    <opc:Field Name="UInt16Value" TypeName="opc:UInt16" />
            '    <opc:Field Name="Int32Value" TypeName="opc:Int32" />
            '    <opc:Field Name="UInt32Value" TypeName="opc:UInt32" />
            '    <opc:Field Name="Int64Value" TypeName="opc:Int64" />
            '    <opc:Field Name="UInt64Value" TypeName="opc:UInt64" />
            '    <opc:Field Name="FloatValue" TypeName="opc:Float" />
            '    <opc:Field Name="DoubleValue" TypeName="opc:Double" />
            '    <opc:Field Name="StringValue" TypeName="opc:String" />
            '    <opc:Field Name="DateTimeValue" TypeName="opc:DateTime" />
            '    <opc:Field Name="GuidValue" TypeName="opc:Guid" />
            '    <opc:Field Name="ByteStringValue" TypeName="opc:ByteString" />
            '    <opc:Field Name="XmlElementValue" TypeName="ua:XmlElement" />
            '    <opc:Field Name="NodeIdValue" TypeName="ua:NodeId" />
            '    <opc:Field Name="ExpandedNodeIdValue" TypeName="ua:ExpandedNodeId" />
            '    <opc:Field Name="QualifiedNameValue" TypeName="ua:QualifiedName" />
            '    <opc:Field Name="LocalizedTextValue" TypeName="ua:LocalizedText" />
            '    <opc:Field Name="StatusCodeValue" TypeName="ua:StatusCode" />
            '    <opc:Field Name="VariantValue" TypeName="ua:Variant" />
            '    <opc:Field Name="EnumerationValue" TypeName="ua:Int32" />
            '    <opc:Field Name="StructureValue" TypeName="ua:ExtensionObject" />
            '    <opc:Field Name="Number" TypeName="ua:Variant" />
            '    <opc:Field Name="Integer" TypeName="ua:Variant" />
            '    <opc:Field Name="UInteger" TypeName="ua:Variant" />
            '  </opc:StructuredType>
            '
            '  <opc:StructuredType Name="ArrayValueDataType" BaseType="ua:ExtensionObject">
            '    <opc:Field Name="NoOfBooleanValue" TypeName="opc:Int32" />
            '    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" LengthField="NoOfBooleanValue" />
            '    <opc:Field Name="NoOfSByteValue" TypeName="opc:Int32" />
        End Sub
    End Class
End Namespace

Object Pascal
VBScript

// Shows how to obtain data type description object for complex data node with OPC UA Complex Data plug-in, and the actual
// content of the data type dictionary.
//
// Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

class procedure ResolveDataTypeDescriptorFromDataTypeEncodingId.Main;
var
  Client: _EasyUAClient;
  ComplexData: _EasyUAClientComplexData;
  DataTypeDictionary: OleVariant;
  DataTypeDictionaryResult: _ValueResult;
  DataTypeDescriptor: _UADataTypeDescriptor;
  DataTypeDescriptorResult: _ValueResult;
  DataTypeId: string;
  DataTypeModelProvider: _UADataTypeModelProvider;
  DataTypeDictionaryProvider: _UADataTypeDictionaryProvider;
  EncodingId: _UAModelNodeDescriptor;
  EncodingIdResult: _ValueResult;
  EncodingName: _UAQualifiedName;
  EndpointDescriptor: string;
  I: Cardinal;
  ModelNodeDescriptor: _UAModelNodeDescriptor;
  Text: string;
begin
  // Define which server and node we will work with.
  EndpointDescriptor :=
    'http://opcua.demo-this.com:51211/UA/SampleServer';
    //or 'https://opcua.demo-this.com:51212/UA/SampleServer/';
    //or 'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';

  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  // Obtain the data type ID.
  //
  // In many cases, you would be able to obtain the data type ID of a particular node by reading its DataType
  // attribute.
  // The sample server, however, shows a more advanced approach in which the data type ID refers to an abstract data type, and
  // the actual values are then sub-types of this base data type. This abstract data type does not have any encodings
  // associated with it and it is therefore not possible to extract its description from the server. We therefore use
  // a hard-coded data type ID for one of the sub-types in this example.
  DataTypeId := 'nsu=http://test.org/UA/Data/ ;i=9440';    // ScalarValueDataType

  // Get the IEasyUAClientComplexData service from the client. This is needed for advanced complex data
  // operations.
  ComplexData := IInterface(Client.GetServiceByName('OpcLabs.EasyOpc.UA.Plugins.ComplexData.IEasyUAClientComplexData, OpcLabs.EasyOpcUA')) as _EasyUAClientComplexData;

  // Get the data type model provider. Provides methods to access data types in OPC UA model.
  DataTypeModelProvider := ComplexData.DataTypeModelProvider;

  // Resolve the data type ID from our data type ID, for encoding name "Default Binary".
  ModelNodeDescriptor := CoUAModelNodeDescriptor.Create;
  ModelNodeDescriptor.EndpointDescriptor.UrlString := EndpointDescriptor;
  ModelNodeDescriptor.NodeDescriptor.NodeId.ExpandedText := DataTypeId;
  EncodingName := CoUAQualifiedName.Create;
  EncodingName.StandardName := 'DefaultBinary';
  EncodingIdResult := DataTypeModelProvider.ResolveEncodingIdFromDataTypeId(ModelNodeDescriptor, EncodingName);
  // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
  if not EncodingIdResult.Succeeded then
  begin
    WriteLn(Format('*** Failure: %s', [EncodingIdResult.ErrorMessageBrief]));
    Exit;
  end;
  EncodingId := IUnknown(EncodingIdResult.Value) as _UAModelNodeDescriptor;

  // Get the data type dictionary provider. Provides methods to access data type dictionaries in OPC UA model.
  DataTypeDictionaryProvider := ComplexData.DataTypeDictionaryProvider;

  // Resolve the data type descriptor from the encoding ID.
  DataTypeDescriptorResult := DataTypeDictionaryProvider.ResolveDataTypeDescriptorFromDataTypeEncodingId(EncodingId);
  // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
  if not DataTypeDescriptorResult.Succeeded then
  begin
    WriteLn(Format('*** Failure: %s', [DataTypeDescriptorResult.ErrorMessageBrief]));
    Exit;
  end;
  DataTypeDescriptor := IUnknown(DataTypeDescriptorResult.Value) as _UADataTypeDescriptor;

  // The data type descriptor contains two pieces of information:
  // The data type dictionary ID: This determines the dictionary where the data type is defined.
  WriteLn(DataTypeDescriptor.DataTypeDictionaryId.ToString);
  // And the data type description: It is a "pointer" into the data type dictionary itself, selecting a specific
  // type definition inside the data type dictionary. The format of it depends on the data type system;
  // in our case, it is a string that is the name of one of the type elements in the XML document of the data type
  // dictionary.
  WriteLn(DataTypeDescriptor.DataTypeDescription);

  // Obtain the actual content of the data type dictionary.
  DataTypeDictionaryResult :=
    DataTypeDictionaryProvider.GetDataTypeDictionaryFromDataTypeDictionaryId(DataTypeDescriptor.DataTypeDictionaryId);
  // Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
  if not DataTypeDictionaryResult.Succeeded then
  begin
    WriteLn(Format('*** Failure: %s', [DataTypeDictionaryResult.ErrorMessageBrief]));
    Exit;
  end;
  DataTypeDictionary := DataTypeDictionaryResult.Value;

  // The data type dictionary returned is an array of bytes; its syntax and semantics depends on the data type
  // system. In our case, we know that the data type dictionary is actually a string encoded in UTF-8.
  for I := VarArrayLowBound(DataTypeDictionary, 1) to VarArrayHighBound(DataTypeDictionary, 1) do
  begin
      Text := Text + Chr(Byte(DataTypeDictionary[I]));
  end;

  WriteLn;
  WriteLn(Text);

  // Example output (truncated):
  //
  //http://opcua.demo-this.com:51211/UA/SampleServer; NodeId="nsu=http://test.org/UA/Data/ ;ns=2;i=11422"
  //ScalarValueDataType
  //
  //<opc:TypeDictionary
  //  xmlns:opc="http://opcfoundation.org/BinarySchema/"
  //  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  //  xmlns:ua="http://opcfoundation.org/UA/"
  //  xmlns:tns="http://test.org/UA/Data/"
  //  DefaultByteOrder="LittleEndian"
  //  TargetNamespace="http://test.org/UA/Data/"
  //>
  //  <!-- This File was generated on 2013-01-22 and supports the specifications supported by version 1.1.334.0 of the OPC UA deliverables. -->
  //  <opc:Import Namespace="http://opcfoundation.org/UA/" Location="Opc.Ua.BinarySchema.bsd"/>
  //
  //  <opc:StructuredType Name="ScalarValueDataType" BaseType="ua:ExtensionObject">
  //    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" />
  //    <opc:Field Name="SByteValue" TypeName="opc:SByte" />
  //    <opc:Field Name="ByteValue" TypeName="opc:Byte" />
  //    <opc:Field Name="Int16Value" TypeName="opc:Int16" />
  //    <opc:Field Name="UInt16Value" TypeName="opc:UInt16" />
  //    <opc:Field Name="Int32Value" TypeName="opc:Int32" />
  //    <opc:Field Name="UInt32Value" TypeName="opc:UInt32" />
  //    <opc:Field Name="Int64Value" TypeName="opc:Int64" />
  //    <opc:Field Name="UInt64Value" TypeName="opc:UInt64" />
  //    <opc:Field Name="FloatValue" TypeName="opc:Float" />
  //    <opc:Field Name="DoubleValue" TypeName="opc:Double" />
  //    <opc:Field Name="StringValue" TypeName="opc:String" />
  //    <opc:Field Name="DateTimeValue" TypeName="opc:DateTime" />
  //    <opc:Field Name="GuidValue" TypeName="opc:Guid" />
  //    <opc:Field Name="ByteStringValue" TypeName="opc:ByteString" />
  //    <opc:Field Name="XmlElementValue" TypeName="ua:XmlElement" />
  //    <opc:Field Name="NodeIdValue" TypeName="ua:NodeId" />
  //    <opc:Field Name="ExpandedNodeIdValue" TypeName="ua:ExpandedNodeId" />
  //    <opc:Field Name="QualifiedNameValue" TypeName="ua:QualifiedName" />
  //    <opc:Field Name="LocalizedTextValue" TypeName="ua:LocalizedText" />
  //    <opc:Field Name="StatusCodeValue" TypeName="ua:StatusCode" />
  //    <opc:Field Name="VariantValue" TypeName="ua:Variant" />
  //    <opc:Field Name="EnumerationValue" TypeName="ua:Int32" />
  //    <opc:Field Name="StructureValue" TypeName="ua:ExtensionObject" />
  //    <opc:Field Name="Number" TypeName="ua:Variant" />
  //    <opc:Field Name="Integer" TypeName="ua:Variant" />
  //    <opc:Field Name="UInteger" TypeName="ua:Variant" />
  //  </opc:StructuredType>
  //
  //  <opc:StructuredType Name="ArrayValueDataType" BaseType="ua:ExtensionObject">
  //    <opc:Field Name="NoOfBooleanValue" TypeName="opc:Int32" />
  //    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" LengthField="NoOfBooleanValue" />
  //    <opc:Field Name="NoOfSByteValue" TypeName="opc:Int32" />

end;

Rem Shows how to obtain data type description object for complex data node with OPC UA Complex Data plug-in, and the actual
Rem content of the data type dictionary.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

' Define which server we will work with.
Dim endpointDescriptor: endpointDescriptor = _
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    '"http://opcua.demo-this.com:51211/UA/SampleServer"  
    '"https://opcua.demo-this.com:51212/UA/SampleServer/"

' Instantiate the client object.
Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.UA.EasyUAClient")

' Obtain the data type ID.
'
' In many cases, you would be able to obtain the data type ID of a particular node by reading its DataType
' attribute. 
' The sample server, however, shows a more advanced approach in which the data type ID refers to an abstract data type, and 
' the actual values are then sub-types of this base data type. This abstract data type does not have any encodings 
' associated with it and it is therefore not possible to extract its description from the server. We therefore use 
' a hard-coded data type ID for one of the sub-types in this example.
Dim dataTypeId: dataTypeId = "nsu=http://test.org/UA/Data/ ;i=9440"    ' ScalarValueDataType

' Get the IEasyUAClientComplexData service from the client. This is needed for advanced complex data 
' operations.
Dim ComplexData: Set ComplexData = _
    Client.GetServiceByName("OpcLabs.EasyOpc.UA.Plugins.ComplexData.IEasyUAClientComplexData, OpcLabs.EasyOpcUA")

' Get the data type model provider. Provides methods to access data types in OPC UA model.
Dim DataTypeModelProvider: Set DataTypeModelProvider = ComplexData.DataTypeModelProvider

' Resolve the data type ID from our data type ID, for encoding name "Default Binary".
Dim ModelNodeDescriptor: Set ModelNodeDescriptor = CreateObject("OpcLabs.EasyOpc.UA.InformationModel.UAModelNodeDescriptor")
ModelNodeDescriptor.EndpointDescriptor.UrlString = endpointDescriptor
ModelNodeDescriptor.NodeDescriptor.NodeId.ExpandedText = dataTypeId
Dim EncodingName: Set EncodingName = CreateObject("OpcLabs.EasyOpc.UA.AddressSpace.UAQualifiedName")
EncodingName.StandardName = "DefaultBinary"
Dim EncodingIdResult: Set EncodingIdResult = _
    DataTypeModelProvider.ResolveEncodingIdFromDataTypeId(ModelNodeDescriptor, EncodingName)
' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
If Not EncodingIdResult.Succeeded Then
    WScript.Echo "*** Failure: "  & EncodingIdResult.Exception.GetBaseException().Message
    WScript.Quit
End If
Dim EncodingId: Set EncodingId = EncodingIdResult.Value

' Get the data type dictionary provider. Provides methods to access data type dictionaries in OPC UA model.
Dim DataTypeDictionaryProvider: Set DataTypeDictionaryProvider = ComplexData.DataTypeDictionaryProvider

' Resolve the data type descriptor from the encoding ID.
Dim DataTypeDescriptorResult: Set DataTypeDescriptorResult = _
    DataTypeDictionaryProvider.ResolveDataTypeDescriptorFromDataTypeEncodingId(EncodingId)
' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
If Not DataTypeDescriptorResult.Succeeded Then
    WScript.Echo "*** Failure: "  & DataTypeDescriptorResult.Exception.GetBaseException().Message
    WScript.Quit
End If
Dim DataTypeDescriptor: Set DataTypeDescriptor = DataTypeDescriptorResult.Value

' The data type descriptor contains two pieces of information:
' The data type dictionary ID: This determines the dictionary where the data type is defined.
WScript.Echo DataTypeDescriptor.DataTypeDictionaryId
' And the data type description: It is a "pointer" into the data type dictionary itself, selecting a specific 
' type definition inside the data type dictionary. The format of it depends on the data type system;
' in our case, it is a string that is the name of one of the type elements in the XML document of the data type
' dictionary.
WScript.Echo DataTypeDescriptor.DataTypeDescription

' Obtain the actual content of the data type dictionary.
Dim DataTypeDictionaryResult: Set DataTypeDictionaryResult = _
    DataTypeDictionaryProvider.GetDataTypeDictionaryFromDataTypeDictionaryId(DataTypeDescriptor.DataTypeDictionaryId)
' Check if the operation succeeded. Use the ThrowIfFailed method instead if you want exception be thrown.
If Not DataTypeDictionaryResult.Succeeded Then
    WScript.Echo "*** Failure: "  & DataTypeDictionaryResult.Exception.GetBaseException().Message
    WScript.Quit
End If
Dim DataTypeDictionary: DataTypeDictionary = DataTypeDictionaryResult.Value

' The data type dictionary returned is an array of bytes; its syntax and semantics depends on the data type 
' system. In our case, we know that the data type dictionary is actually a string encoded in UTF-8.
Dim text
Dim i: For i = LBound(DataTypeDictionary) To UBound(DataTypeDictionary)
    text = text & Chr(DataTypeDictionary(i))
Next
WScript.Echo
WScript.Echo text


' Example output (truncated):
'
'http://opcua.demo-this.com:51211/UA/SampleServer; NodeId="nsu=http:'test.org/UA/Data/;ns=2;i=11422"
'ScalarValueDataType
'
'<opc:TypeDictionary
'  xmlns:opc="http:'opcfoundation.org/BinarySchema/"
'  xmlns:xsi="http:'www.w3.org/2001/XMLSchema-instance"
'  xmlns:ua="http:'opcfoundation.org/UA/"
'  xmlns:tns="http:'test.org/UA/Data/"
'  DefaultByteOrder="LittleEndian"
'  TargetNamespace="http:'test.org/UA/Data/"
'>
'  <!-- This File was generated on 2013-01-22 and supports the specifications supported by version 1.1.334.0 of the OPC UA deliverables. -->
'  <opc:Import Namespace="http:'opcfoundation.org/UA/" Location="Opc.Ua.BinarySchema.bsd"/>
'
'  <opc:StructuredType Name="ScalarValueDataType" BaseType="ua:ExtensionObject">
'    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" />
'    <opc:Field Name="SByteValue" TypeName="opc:SByte" />
'    <opc:Field Name="ByteValue" TypeName="opc:Byte" />
'    <opc:Field Name="Int16Value" TypeName="opc:Int16" />
'    <opc:Field Name="UInt16Value" TypeName="opc:UInt16" />
'    <opc:Field Name="Int32Value" TypeName="opc:Int32" />
'    <opc:Field Name="UInt32Value" TypeName="opc:UInt32" />
'    <opc:Field Name="Int64Value" TypeName="opc:Int64" />
'    <opc:Field Name="UInt64Value" TypeName="opc:UInt64" />
'    <opc:Field Name="FloatValue" TypeName="opc:Float" />
'    <opc:Field Name="DoubleValue" TypeName="opc:Double" />
'    <opc:Field Name="StringValue" TypeName="opc:String" />
'    <opc:Field Name="DateTimeValue" TypeName="opc:DateTime" />
'    <opc:Field Name="GuidValue" TypeName="opc:Guid" />
'    <opc:Field Name="ByteStringValue" TypeName="opc:ByteString" />
'    <opc:Field Name="XmlElementValue" TypeName="ua:XmlElement" />
'    <opc:Field Name="NodeIdValue" TypeName="ua:NodeId" />
'    <opc:Field Name="ExpandedNodeIdValue" TypeName="ua:ExpandedNodeId" />
'    <opc:Field Name="QualifiedNameValue" TypeName="ua:QualifiedName" />
'    <opc:Field Name="LocalizedTextValue" TypeName="ua:LocalizedText" />
'    <opc:Field Name="StatusCodeValue" TypeName="ua:StatusCode" />
'    <opc:Field Name="VariantValue" TypeName="ua:Variant" />
'    <opc:Field Name="EnumerationValue" TypeName="ua:Int32" />
'    <opc:Field Name="StructureValue" TypeName="ua:ExtensionObject" />
'    <opc:Field Name="Number" TypeName="ua:Variant" />
'    <opc:Field Name="Integer" TypeName="ua:Variant" />
'    <opc:Field Name="UInteger" TypeName="ua:Variant" />
'  </opc:StructuredType>
'
'  <opc:StructuredType Name="ArrayValueDataType" BaseType="ua:ExtensionObject">
'    <opc:Field Name="NoOfBooleanValue" TypeName="opc:Int32" />
'    <opc:Field Name="BooleanValue" TypeName="opc:Boolean" LengthField="NoOfBooleanValue" />
'    <opc:Field Name="NoOfSByteValue" TypeName="opc:Int32" />

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

_UADataTypeDescriptor Interface
_UADataTypeDescriptor Members

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