Determines whether the node descriptor matches another node descriptor.
Syntax
Parameters
- other
- A UANodeDescriptor. The node descriptor to match against.
Because the UANodeDescriptor has implicit conversions from OpcLabs.EasyOpc.UA.AddressSpace.UANodeId, OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement, OpcLabs.EasyOpc.UA.Navigation.UABrowsePath and System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.AddressSpace.UANodeId object (representing the Id of the OPC UA node), a node element object (from OPC UA browsing), OpcLabs.EasyOpc.UA.Navigation.UABrowsePath object (representing OPC UA absolute browse path), or a string (with expanded node Id text) in place of this parameter, and the corresponding node descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the FromString, FromUABrowsePath, FromUANodeElement or FromUANodeId static method instead.
If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode can be used in the same way to simply pass the server node in place of this parameter, which will use its OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode.EffectiveNodeDescriptor property for the operation.
The value of this parameter cannot be null
(Nothing
in Visual Basic).
Return Value
Returns true if two node descriptors match; otherwise, returns false.
Exceptions
Exception | Description |
System.ArgumentNullException |
A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.
This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception. |
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.')
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