OPC Studio User's Guide and Reference
FieldData Property (StructuredData)
Example 



OpcLabs.BaseLib Assembly > OpcLabs.BaseLib.DataTypeModel Namespace > StructuredData Class : FieldData Property
Dictionary of field data values, keyed by the field name.
Syntax
'Declaration
 
Public Property FieldData As FieldDataDictionary
'Usage
 
Dim instance As StructuredData
Dim value As FieldDataDictionary
 
instance.FieldData = value
 
value = instance.FieldData
public FieldDataDictionary FieldData {get; set;}
public:
property FieldDataDictionary^ FieldData {
   FieldDataDictionary^ get();
   void set (    FieldDataDictionary^ value);
}

Property Value

The value of this property cannot be null (Nothing in Visual Basic).

The individual elements of the property value can be null (Nothing in Visual Basic).

Remarks

Relation of StructuredData and its constituents is shown on the following picture:

.

Example
// Shows how to write complex data with OPC UA Complex Data plug-in.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.BaseLib.DataTypeModel;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.ComplexData;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.ComplexData._EasyUAClient
{
    class WriteValue
    {
        public static void Main1()
        {
            // Define which server and node 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/"
            UANodeDescriptor nodeDescriptor =
                "nsu=http://test.org/UA/Data/ ;i=10239"; // [ObjectsFolder]/Data.Static.Scalar.StructureValue

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

            // Read a node which returns complex data. 
            // We know that this node returns complex data, so we can type cast to UAGenericObject.
            Console.WriteLine("Reading...");
            UAGenericObject genericObject;
            try
            {
                genericObject = (UAGenericObject)client.ReadValue(endpointDescriptor, nodeDescriptor);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }


            // Modify the data read.
            // This node returns one of the two data types, randomly (this is not common, usually the type is fixed). The
            // data types are sub-types of one common type which the data type of the node. We therefore use the data type 
            // ID in the returned UAGenericObject to detect which data type has been returned.

            // For processing the internals of the data, refer to examples for GenericData and DataType classes.
            // We know how the data is structured, and have hard-coded a logic that modifies certain values inside. It is
            // also possible to discover the structure of the data type in the program, and write generic clients that can 
            // cope with any kind of complex data.
            //
            // Note that the code below is not fully robust - it will throw an exception if the data is not as expected.
            Console.WriteLine("Modifying...");
            Console.WriteLine(genericObject.DataTypeId);
            if (genericObject.DataTypeId.NodeDescriptor.Match("nsu=http://test.org/UA/Data/ ;i=9440"))  // ScalarValueDataType
            {
                // Negate the byte in the "ByteValue" field.
                var structuredData = (StructuredData)genericObject.GenericData;
                var byteValue = (PrimitiveData)structuredData.FieldData["ByteValue"];
                byteValue.Value = (Byte)~((Byte)byteValue.Value);
                Console.WriteLine(byteValue.Value);
            }
            else if (genericObject.DataTypeId.NodeDescriptor.Match("nsu=http://test.org/UA/Data/ ;i=9669")) // ArrayValueDataType
            {
                // Negate bytes at indexes 0 and 1 of the array in the "ByteValue" field.
                var structuredData = (StructuredData)genericObject.GenericData;
                var byteValue = (SequenceData)structuredData.FieldData["ByteValue"];
                var element0 = (PrimitiveData)byteValue.Elements[0];
                var element1 = (PrimitiveData)byteValue.Elements[1];
                element0.Value = (Byte)~((Byte)element0.Value);
                element1.Value = (Byte)~((Byte)element1.Value);
                Console.WriteLine(element0.Value);
                Console.WriteLine(element1.Value);
            }


            // Write the modified complex data back to the node.
            // The data type ID in the UAGenericObject is borrowed without change from what we have read, so that the server
            // knows which data type we are writing. The data type ID not necessary if writing precisely the same data type
            // as the node has (not a subtype).
            Console.WriteLine("Writing...");
            try
            {
                client.WriteValue(endpointDescriptor, nodeDescriptor, genericObject);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
            }
        }
    }
}
' Shows how to write complex data with OPC UA Complex Data plug-in.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System
Imports OpcLabs.BaseLib.DataTypeModel
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.ComplexData
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace ComplexData._EasyUAClient

    Friend Class WriteValue

        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/"

            ' Define which node we will work with.
            Dim nodeDescriptor As UANodeDescriptor = _
                "nsu=http://test.org/UA/Data/ ;i=10239"  ' [ObjectsFolder]/Data.Static.Scalar.StructureValue

            ' Instantiate the client object.
            Dim client = New EasyUAClient

            ' Read a node which returns complex data. 
            ' We know that this node returns complex data, so we can type cast to UAGenericObject.
            Console.WriteLine("Reading...")
            Dim genericObject As UAGenericObject
            Try
                genericObject = CType(client.ReadValue(endpointDescriptor, nodeDescriptor), UAGenericObject)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try


            ' Modify the data read.
            ' This node returns one of the two data types, randomly (this is not common, usually the type is fixed). The
            ' data types are sub-types of one common type which the data type of the node. We therefore use the data type 
            ' ID in the returned UAGenericObject to detect which data type has been returned.
            ' For processing the internals of the data, refer to examples for GenericData and DataType classes.
            ' We know how the data is structured, and have hard-coded a logic that modifies certain values inside. It is
            ' also possible to discover the structure of the data type in the program, and write generic clients that can 
            ' cope with any kind of complex data.
            '
            ' Note that the code below is not fully robust - it will throw an exception if the data is not as expected.
            Console.WriteLine("Modifying...")
            Console.WriteLine(genericObject.DataTypeId)
            If genericObject.DataTypeId.NodeDescriptor.Match("nsu=http://test.org/UA/Data/ ;i=9440") Then    ' ScalarValueDataType
                ' Negate the byte in the "ByteValue" field.
                Dim structuredData = CType(genericObject.GenericData, StructuredData)
                Dim byteValue = CType(structuredData.FieldData("ByteValue"), PrimitiveData)
                byteValue.Value = CType(Not CType(byteValue.Value, Byte), Byte)
                Console.WriteLine(byteValue.Value)
            ElseIf genericObject.DataTypeId.NodeDescriptor.Match("nsu=http://test.org/UA/Data/ ;i=9669") Then    ' ArrayValueDataType
                ' Negate bytes at indexes 0 and 1 of the array in the "ByteValue" field.
                Dim structuredData = CType(genericObject.GenericData, StructuredData)
                Dim byteValue = CType(structuredData.FieldData("ByteValue"), SequenceData)
                Dim element0 = CType(byteValue.Elements(0), PrimitiveData)
                Dim element1 = CType(byteValue.Elements(1), PrimitiveData)
                element0.Value = CType(Not CType(element0.Value, Byte), Byte)
                element1.Value = CType(Not CType(element1.Value, Byte), Byte)
                Console.WriteLine(element0.Value)
                Console.WriteLine(element1.Value)
            End If


            ' Write the modified complex data back to the node.
            ' The data type ID in the UAGenericObject is borrowed without change from what we have read, so that the server
            ' knows which data type we are writing. The data type ID not necessary if writing precisely the same data type
            ' as the node has (not a subtype).
            Console.WriteLine("Writing...")
            Try
                client.WriteValue(endpointDescriptor, nodeDescriptor, genericObject)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try
        End Sub
    End Class
End Namespace
// Shows how to write complex data with OPC UA Complex Data plug-in.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

class procedure WriteValue.Main;
var
  ArrayValueDataType: _UANodeDescriptor;
  ByteValue: _PrimitiveData;
  ByteValue2: _SequenceData;
  Client: _EasyUAClient;
  Element0, Element1: _PrimitiveData;
  EndpointDescriptor: string;
  GenericObject: _UAGenericObject;
  NodeDescriptor: string;
  ScalarValueDataType: _UANodeDescriptor;
  StructuredData: _StructuredData;
begin
  // Define which server and node we will work with.
  EndpointDescriptor := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  NodeDescriptor := 'nsu=http://test.org/UA/Data/ ;i=10239';  // [ObjectsFolder]/Data.Static.Scalar.StructureValue

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

  // Read a node which returns complex data.
  // We know that this node returns complex data, so we can type cast to UAGenericObject.
  WriteLn('Reading...');

  try
    GenericObject := _UAGenericObject(IUnknown(Client.ReadValue(EndpointDescriptor, NodeDescriptor)));
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

  // Modify the data read.
  // This node returns one of the two data types, randomly (this is not common, usually the type is fixed). The
  // data types are sub-types of one common type which the data type of the node. We therefore use the data type
  // ID in the returned UAGenericObject to detect which data type has been returned.

  // For processing the internals of the data, refer to examples for GenericData and DataType classes.
  // We know how the data is structured, and have hard-coded a logic that modifies certain values inside. It is
  // also possible to discover the structure of the data type in the program, and write generic clients that can
  // cope with any kind of complex data.
  //
  // Note that the code below is not fully robust - it will throw an exception if the data is not as expected.

  WriteLn('Modifying...');
  WriteLn(GenericObject.DataTypeId.ToString);
  ScalarValueDataType := CoUANodeDescriptor.Create;
  ScalarValueDataType.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=9440'; // ScalarValueDataType
  if GenericObject.DataTypeId.NodeDescriptor.Match(ScalarValueDataType) then
  begin
    // Negate the byte in the "ByteValue" field.
    StructuredData := IUnknown(GenericObject.GenericData) as _StructuredData;
    ByteValue := IUnknown(StructuredData.FieldData['ByteValue']) as _PrimitiveData;
    ByteValue.Value := Byte(not (Byte(byteValue.Value)));
    WriteLn(ByteValue.Value);
  end
  else
  begin
    ArrayValueDataType := CoUANodeDescriptor.Create;
    ArrayValueDataType.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=9669'; // ArrayValueDataType
    if GenericObject.DataTypeId.Nodedescriptor.Match(ArrayValueDataType) then
    begin
      // Negate bytes at indexes 0 and 1 of the array in the "ByteValue" field.
      StructuredData := IUnknown(GenericObject.GenericData) as _StructuredData;
      ByteValue2 := IUnknown(StructuredData.FieldData['ByteValue']) as _SequenceData;
      Element0 := IUnknown(ByteValue2.Elements[0]) as _PrimitiveData;
      Element1 := IUnknown(ByteValue2.Elements[1]) as _PrimitiveData;
      Element0.Value := Byte(not (Byte(element0.Value)));
      Element1.Value := Byte(not (Byte(element1.Value)));
      WriteLn(Element0.Value);
      WriteLn(Element1.Value);
    end;
  end;

  // Write the modified complex data back to the node.
  // The data type ID in the UAGenericObject is borrowed without change from what we have read, so that the server
  // knows which data type we are writing. The data type ID not necessary if writing precisely the same data type
  // as the node has (not a subtype).
  WriteLn('Writing...');
  try
    Client.WriteValue(EndpointDescriptor, NodeDescriptor, GenericObject);
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

end;
// Shows how to write complex data with OPC UA Complex Data plug-in.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in PHP on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PHP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

// Define which server and node we will work with.
$EndpointDescriptor = 
    //"http://opcua.demo-this.com:51211/UA/SampleServer";
    //"https://opcua.demo-this.com:51212/UA/SampleServer/";
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
$NodeDescriptor = "nsu=http://test.org/UA/Data/ ;i=10239";  // [ObjectsFolder]/Data.Static.Scalar.StructureValue

// Instantiate the client object
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");

// Read a node which returns complex data.
// We know that this node returns complex data, so we can type cast to UAGenericObject.
printf("Reading...\n");

try
{
    $GenericObject = $Client->ReadValue($EndpointDescriptor, $NodeDescriptor);
}
catch (com_exception $e)
{
    printf("*** Failure: %s\n", $e->getMessage());
    Exit();
}

// Modify the data read.
// This node returns one of the two data types, randomly (this is not common, usually the type is fixed). The
// data types are sub-types of one common type which the data type of the node. We therefore use the data type
// ID in the returned UAGenericObject to detect which data type has been returned.

// For processing the internals of the data, refer to examples for GenericData and DataType classes.
// We know how the data is structured, and have hard-coded a logic that modifies certain values inside. It is
// also possible to discover the structure of the data type in the program, and write generic clients that can
// cope with any kind of complex data.
//
// Note that the code below is not fully robust - it will throw an exception if the data is not as expected.

printf("Modifying...\n");
printf("%s\n", $GenericObject->DataTypeId);
$ScalarValueDataType = new COM("OpcLabs.EasyOpc.UA.UANodeDescriptor");
$ScalarValueDataType->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=9440"; // ScalarValueDataType
if ($GenericObject->DataTypeId->NodeDescriptor->Match($ScalarValueDataType)) {
    // Negate the byte in the "ByteValue" field.
    $StructuredData = $GenericObject->GenericData->AsStructuredData();
    $ByteValue = $StructuredData->FieldData["ByteValue"]->AsPrimitiveData();
    $ByteValue->Value = ~($ByteValue->Value) & 255;
    printf("%s\n", $ByteValue->Value);
}
else {
    $ArrayValueDataType = new COM("OpcLabs.EasyOpc.UA.UANodeDescriptor");
    $ArrayValueDataType->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=9669"; // ArrayValueDataType
    if ($GenericObject->DataTypeId->Nodedescriptor->Match($ArrayValueDataType)) {
        // Negate bytes at indexes 0 and 1 of the array in the "ByteValue" field.
        $StructuredData = $GenericObject->GenericData->AsStructuredData();
        $ByteValue2 = $StructuredData->FieldData["ByteValue"]->AsSequenceData();
        $Element0 = $ByteValue2->Elements[0]->AsPrimitiveData();
        $Element1 = $ByteValue2->Elements[1]->AsPrimitiveData();
        $Element0->Value = ~($Element0->Value) & 255;
        $Element1->Value = ~($Element1->Value) & 255;
        printf("%s\n", $Element0->Value);
        printf("%s\n", $Element1->Value);
    }
}

// Write the modified complex data back to the node.
// The data type ID in the UAGenericObject is borrowed without change from what we have read, so that the server
// knows which data type we are writing. The data type ID not necessary if writing precisely the same data type
// as the node has (not a subtype).
printf("Writing...\n");
try
{
    $Client->WriteValue($EndpointDescriptor, $NodeDescriptor, $GenericObject);
}
catch (com_exception $e)
{
    printf("Failure: %s\n", $e->getMessage());
    Exit();
}
# Shows how to write complex data with OPC UA Complex Data plug-in.
#
# 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 .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.BaseLib.DataTypeModel import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel 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/'

# [ObjectsFolder]/Data.Static.Scalar.StructureValue
nodeDescriptor = UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10239')

# Instantiate the client object.
client = EasyUAClient()

# Read a node which returns complex data.
# We know that this node returns complex data, so we can type cast to UAGenericObject.
try:
    print('Reading...')
    genericObject = IEasyUAClientExtension.ReadValue(client, endpointDescriptor, nodeDescriptor)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Modify the data read.
# This node returns one of the two data types, randomly (this is not common, usually the type is fixed). The
# data types are sub-types of one common type which the data type of the node. We therefore use the data type
# ID in the returned UAGenericObject to detect which data type has been returned.
#
# For processing the internals of the data, refer to examples for GenericData and DataType classes.
# We know how the data is structured, and have hard-coded a logic that modifies certain values inside. It is
# also possible to discover the structure of the data type in the program, and write generic clients that can
# cope with any kind of complex data.
#
# Note that the code below is not fully robust - it will throw an exception if the data is not as expected.
print ('Modifying...')
print(genericObject.DataTypeId)
if genericObject.DataTypeId.NodeDescriptor.Match(UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=9440')):  # ScalarValueDataType
    # Negate the byte in the "ByteValue" field.
    structuredData = genericObject.GenericData
    byteValue = structuredData.FieldData.get_Item('ByteValue')  # PrimitiveData
    byteValue.Value = (~byteValue.Value) & 0xFF
    print(byteValue.Value)
elif genericObject.DataTypeId.NodeDescriptor.Match(UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=9669')): # ArrayValueDataType
    # Negate bytes at indexes 0 and 1 of the array in the "ByteValue" field.
    structuredData = genericObject.GenericData
    byteValue = structuredData.FieldData.get_Item('ByteValue')  # SequenceData
    element0 = byteValue.Elements.get_Item(0)    # PrimitiveData
    element1 = byteValue.Elements.get_Item(1)    # PrimitiveData
    element0.Value = (~element0.Value) & 0xFF
    element1.Value = (~element1.Value) & 0xFF
    print(element0.Value)
    print(element1.Value)


# Write the modified complex data back to the node.
# The data type ID in the UAGenericObject is borrowed without change from what we have read, so that the server
# knows which data type we are writing. The data type ID not necessary if writing precisely the same data type
# as the node has (not a subtype).
try:
    print('Writing...')
    IEasyUAClientExtension.WriteValue(client, endpointDescriptor, nodeDescriptor, genericObject)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)


print()
print('Finished.')
// Shows how to process generic data type, displaying some of its properties, recursively.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using System.Collections.Generic;
using OpcLabs.BaseLib.DataTypeModel;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.ComplexData;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.ComplexData._GenericData
{
    class DataTypeKind1
    {
        public static void Main1()
        {
            // Define which server and node 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/"
            UANodeDescriptor nodeDescriptor =
                "nsu=http://test.org/UA/Data/ ;i=10239"; // [ObjectsFolder]/Data.Static.Scalar.StructureValue

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

            // Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
            UAGenericObject genericObject;
            try
            {
                genericObject = (UAGenericObject)client.ReadValue(endpointDescriptor, nodeDescriptor);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Process the generic data type. We will inspect some of its properties, and dump them.
            ProcessGenericData(genericObject.GenericData, maximumDepth: 3);
        }
        

        // Process the generic data type. Its structure can sometimes be quite deep, therefore we are limiting the depth
        // of the recursion using maximumDepth.
        public static void ProcessGenericData(GenericData genericData, int maximumDepth)
        {
            if (maximumDepth == 0)
                return;

            Console.WriteLine();
            Console.WriteLine("genericData.DataType: {0}", genericData.DataType);

            switch (genericData.DataTypeKind)
            {
                case DataTypeKind.Enumeration:
                    Console.WriteLine("The generic data is an enumeration.");
                    var enumerationData = (EnumerationData) genericData;
                    Console.WriteLine("Its value is {0}.", enumerationData.Value);
                    // There is also a ValueName that you can inspect (if known).
                    break;

                case DataTypeKind.Opaque:
                    Console.WriteLine("The generic data is opaque.");
                    var opaqueData = (OpaqueData) genericData;
                    Console.WriteLine("Its size is {0} bits.", opaqueData.SizeInBits);
                    Console.WriteLine("The data bytes are {0}.", BitConverter.ToString(opaqueData.ByteArray));
                    // Use the Value property (a BitArray) if you need to access the value bit by bit.
                    break;

                case DataTypeKind.Primitive:
                    Console.WriteLine("The generic data is primitive.");
                    var primitiveData = (PrimitiveData) genericData;
                    Console.WriteLine("Its value is \"{0}\".", primitiveData.Value);
                    break;

                case DataTypeKind.Sequence:
                    Console.WriteLine("The generic data is a sequence.");
                    var sequenceData = (SequenceData) genericData;
                    Console.WriteLine("It has {0} elements.", sequenceData.Elements.Count);
                    Console.WriteLine("A dump of the elements follows.");
                    foreach (GenericData element in sequenceData.Elements)
                        ProcessGenericData(element, maximumDepth - 1);
                    break;

                case DataTypeKind.Structured:
                    Console.WriteLine("The generic data is structured.");
                    var structuredData = (StructuredData) genericData;
                    Console.WriteLine("It has {0} field data members.", structuredData.FieldData.Count);
                    Console.WriteLine("The names of the fields are: {0}.",
                        String.Join(", ", structuredData.FieldData.Keys));

                    Console.WriteLine("A dump of each of the fields follows.");
                    foreach (KeyValuePair<string, GenericData> pair in structuredData.FieldData)
                    {
                        Console.WriteLine();
                        Console.WriteLine("Field name: {0}", pair.Key);
                        ProcessGenericData(pair.Value, maximumDepth - 1);
                    }
                    break;

                case DataTypeKind.Union:
                    Console.WriteLine("The generic data is a union.");
                    var unionData = (UnionData)genericData;
                    Console.WriteLine("The name of current field is: {0}", unionData.FieldName);
                    Console.WriteLine("Current field value is: {0}", unionData.FieldValue);
                    break;
            }
        }
    }
}
' Shows how to process generic data type, displaying some of its properties, recursively.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.BaseLib.DataTypeModel
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.ComplexData
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace ComplexData._GenericData

    Friend Class DataTypeKind1

        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/"

            ' Define which node we will work with.
            Dim nodeDescriptor As UANodeDescriptor = _
                "nsu=http://test.org/UA/Data/ ;i=10239"  ' [ObjectsFolder]/Data.Static.Scalar.StructureValue

            ' Instantiate the client object.
            Dim client = New EasyUAClient

            ' Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
            Dim genericObject As UAGenericObject
            Try
                genericObject = CType(client.ReadValue(endpointDescriptor, nodeDescriptor), UAGenericObject)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Process the generic data type. We will inspect some of its properties, and dump them.
            ProcessGenericData(genericObject.GenericData, maximumDepth:=2)
        End Sub


        ' Process the generic data type. Its structure can sometimes be quite deep, therefore we are limiting the depth
        ' of the recursion using maximumDepth.
        Public Shared Sub ProcessGenericData(ByVal genericData As GenericData, ByVal maximumDepth As Integer)
            If (maximumDepth = 0) Then
                Return
            End If

            Console.WriteLine()
            Console.WriteLine("genericData.DataType: {0}", genericData.DataType)

            Select Case (genericData.DataTypeKind)
                Case DataTypeKind.Enumeration
                    Console.WriteLine("The generic data is an enumeration.")
                    Dim enumerationData = CType(genericData, EnumerationData)
                    Console.WriteLine("Its value is {0}.", enumerationData.Value)
                    ' There is also a ValueName that you can inspect (if known).

                Case DataTypeKind.Opaque
                    Console.WriteLine("The generic data is opaque.")
                    Dim opaqueData = CType(genericData, OpaqueData)
                    Console.WriteLine("Its size is {0} bits.", opaqueData.SizeInBits)
                    Console.WriteLine("The data bytes are {0}.", BitConverter.ToString(opaqueData.ByteArray))
                    ' Use the Value property (a BitArray) if you need to access the value bit by bit.

                Case DataTypeKind.Primitive
                    Console.WriteLine("The generic data is primitive.")
                    Dim primitiveData = CType(genericData, PrimitiveData)
                    Console.WriteLine("Its value is ""{0}"".", primitiveData.Value)

                Case DataTypeKind.Sequence
                    Console.WriteLine("The generic data is a sequence.")
                    Dim sequenceData = CType(genericData, SequenceData)
                    Console.WriteLine("It has {0} elements.", sequenceData.Elements.Count)
                    Console.WriteLine("A dump of the elements follows.")
                    For Each element As GenericData In sequenceData.Elements
                        ProcessGenericData(element, (maximumDepth - 1))
                    Next

                Case DataTypeKind.Structured
                    Console.WriteLine("The generic data is structured.")
                    Dim structuredData = CType(genericData, StructuredData)
                    Console.WriteLine("It has {0} field data members.", structuredData.FieldData.Count)
                    Console.WriteLine("The names of the fields are: {0}.", String.Join(", ", structuredData.FieldData.Keys))

                    Console.WriteLine("A dump of each of the fields follows.")
                    For Each pair As KeyValuePair(Of String, GenericData) In structuredData.FieldData
                        Console.WriteLine()
                        Console.WriteLine("Field name: {0}", pair.Key)
                        ProcessGenericData(pair.Value, (maximumDepth - 1))
                    Next

                Case DataTypeKind.Union
                    Console.WriteLine("The generic data is union.")
                    Dim unionData = CType(genericData, UnionData)
                    Console.WriteLine("The name of current field is: {0}", unionData.FieldName)
                    Console.WriteLine("Current field value is: {0}", unionData.FieldValue)
            End Select

        End Sub
    End Class
End Namespace
// Shows how to process generic data type, displaying some of its properties, recursively
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

class procedure DataTypeKind1.Main;
var
  Client: _EasyUAClient;
  EndpointDescriptor: string;
  GenericObject: _UAGenericObject;
  NodeDescriptor: string;
begin
  EndpointDescriptor := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  NodeDescriptor := 'nsu=http://test.org/UA/Data/ ;i=10239';  // [ObjectsFolder]/Data.Static.Scalar.StructureValue

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

  // Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.

  try
    GenericObject := _UAGenericObject(IUnknown(Client.ReadValue(EndpointDescriptor, NodeDescriptor)));
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

  // Process the generic data type. We will inspect some of its properties, and dump them.
  ProcessGenericData(GenericObject.GenericData, 2);
end;

Function VariantToBytes(Const Value: OleVariant): TBytes;
Var
  Size: Integer;
  pData: Pointer;
Begin
  Size := Succ(VarArrayHighBound(Value, 1) - VarArrayLowBound(Value, 1));
  SetLength(Result, Size);
  pData := VarArrayLock(Value);
  Try
    Move(pData^, Pointer(Result)^, Size);
  Finally
    VarArrayUnlock(Value);
  End;
End;

class procedure DatatypeKind1.ProcessGenericData(GenericData: OpcLabs_BaseLib_TLB._GenericData; MaximumDepth: Cardinal);
var
  ByteArray: OleVariant;
  Count: Cardinal;
  Element: OleVariant;
  ElementEnumerator: IEnumVARIANT;
  EnumerationData: _EnumerationData;
  First: boolean;
  Keys: string;
  OpaqueData: _OpaqueData;
  PrimitiveData: _PrimitiveData;
  SequenceData: _SequenceData;
  StructuredData: _StructuredData;
  Value: OpcLabs_BaseLib_TLB._GenericData;
begin
  if MaximumDepth = 0 then
    Exit;

  WriteLn;
  WriteLn('genericData.DataType: ', GenericData.DataType.ToString);

  case GenericData.DataTypeKind of
    DataTypeKind_Enumeration:
      begin
        WriteLn('The generic data is an enumeration.');
        EnumerationData := GenericData as _EnumerationData;
        WriteLn(Format('Its value is %s.', [EnumerationData.Value.ToString]));
        // There is also a ValueName that you can inspect (if known).
      end;
    DataTypeKind_Opaque:
      begin
        WriteLn('The generic data is opaque.');
        OpaqueData := GenericData as _OpaqueData;
        WriteLn(Format('Its size is %d bits.', [OpaqueData.SizeInBits]));
        TVarData(ByteArray).VType := varArray;
        TVarData(ByteArray).VArray := PVarArray(OpaqueData.ByteArray);
        WriteLn(Format('The data bytes are %s.', [TEncoding.ANSI.GetString(VariantToBytes(ByteArray))]));
        // Use the Value property (a BitArray) if you need to access the value bit by bit.
      end;
    DataTypeKind_Primitive:
      begin
        WriteLn('The generic data is primitive.');
        PrimitiveData := GenericData as _PrimitiveData;
        WriteLn(Format('Its value is "%s".', [PrimitiveData.Value]));
      end;
    DataTypeKind_Sequence:
      begin
        WriteLn('The generic data is a sequence.');
        SequenceData := GenericData as _SequenceData;
        WriteLn(Format('It has %s elements.', [SequenceData.Elements.Count.ToString]));
        WriteLn('A dump of the elements follows.');
        ElementEnumerator := SequenceData.Elements.GetEnumerator;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          ProcessGenericData(IUnknown(Element) as OpcLabs_BaseLib_TLB._GenericData, MaximumDepth - 1);
        end;
      end;
    DataTypeKind_Structured:
      begin
        WriteLn('The generic data is structured.');
        StructuredData := GenericData as _StructuredData;
        WriteLn(Format('It has %s field data members.', [StructuredData.FieldData.Count.ToString]));
        ElementEnumerator := StructuredData.FieldData.GetEnumerator;
        Keys := '';
        First := True;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          if First then
            First := False
          else
            Keys := Keys + ', ';
          Keys := Keys + Element.Key;
        end;
        WriteLn(Format('The names of the fields are: %s.', [Keys]));

        WriteLn('A dump of each of the fields follows.');
        ElementEnumerator := StructuredData.FieldData.GetEnumerator;
        while (ElementEnumerator.Next(1, Element, Count) = S_OK) do
        begin
          WriteLn;
          WriteLn(Format('Field name: %s', [Element.Key]));
          Value := IUnknown(Element.Value) as OpcLabs_BaseLib_TLB._GenericData;
          ProcessGenericData(Value, MaximumDepth - 1);
        end;
      end;
  end;

end;

# Shows how to process generic data type, displaying some of its properties, recursively.
#
# 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 .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.BaseLib.DataTypeModel import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


def processGenericData(genericData, maximumDepth):
    if maximumDepth == 0:
        print('* Reached maximum depth *')
        return

    print()
    print('genericData.DataType: ', genericData.DataType, sep='')

    dataTypeKind = genericData.DataTypeKind
    if dataTypeKind == DataTypeKind.Enumeration:
        print('The generic data is an enumeration.')
        enumerationData = genericData
        print('Its value is ', enumerationData.Value, '.', sep='')
        # There is also a ValueName that you can inspect (if known).

    elif dataTypeKind == DataTypeKind.Opaque:
        print('The generic data is opaque.')
        opaqueData = genericData
        print('Its size is ', opaqueData.SizeInBits, ' bits.', sep='')
        print('The data bytes are ', BitConverter.ToString(opaqueData.ByteArray), '.', sep='')
        # Use the Value property (a BitArray) if you need to access the value bit by bit.

    elif dataTypeKind == DataTypeKind.Primitive:
        print('The generic data is primitive.')
        primitiveData = genericData
        print('Its value is "', primitiveData.Value, '".', sep='')

    elif dataTypeKind == DataTypeKind.Sequence:
        print('The generic data is a sequence.')
        sequenceData = genericData
        print('It has ', sequenceData.Elements.Count, ' elements.', sep='')
        print('A dump of the elements follows.')
        for element in sequenceData.Elements:
            processGenericData(element, maximumDepth - 1)

    elif dataTypeKind == DataTypeKind.Structured:
        print('The generic data is structured.')
        structuredData = genericData
        print('It has ', structuredData.FieldData.Count, ' field data members.', sep='')
        print('The names of the fields are: ', end='')
        for i, name in enumerate(structuredData.FieldData.Keys):
            if i != 0:
                print(', ', end='')
            print(name, end='')
        print('.')

        print('A dump of each of the fields follows.')
        for pair in structuredData.FieldData:
            print()
            print('Field name: ', pair.Key, sep='')
            processGenericData(pair.Value, maximumDepth - 1)

    elif dataTypeKind == DataTypeKind.Union:
        print('The generic data is a union.')
        unionData = genericData
        print('The name of current field is: ', unionData.FieldName, sep='')
        print('Current field value is: ', unionData.FieldValue, end='')


# Define which server and node we will work with.
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/'

# [ObjectsFolder]/Data.Static.Scalar.StructureValue
nodeDescriptor = UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10239')

# Instantiate the client object.
client = EasyUAClient()

# Read a node. We know that this node returns complex data, so we can type cast to UAGenericObject.
try:
    print('Reading...')
    genericObject = IEasyUAClientExtension.ReadValue(client, endpointDescriptor, nodeDescriptor)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()
print('Reading successful.')

# Process the generic data type. We will inspect some of its properties, and dump them.
processGenericData(genericObject.GenericData, 3)

print()
print('Finished.')
Requirements

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

See Also