Browse(IEasyUAClient,UAEndpointDescriptor,UANodeDescriptor,UABrowseParameters) Method

Browses the nodes in server's address space, given an endpoint descriptor, node descriptor, and browse parameters.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function Browse( _
   ByVal client As IEasyUAClient, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal nodeDescriptor As UANodeDescriptor, _
   ByVal browseParameters As UABrowseParameters _
) As UANodeElementCollection

'Usage
 
Dim client As IEasyUAClient
Dim endpointDescriptor As UAEndpointDescriptor
Dim nodeDescriptor As UANodeDescriptor
Dim browseParameters As UABrowseParameters
Dim value As UANodeElementCollection
 
value = IEasyUAClientExtension.Browse(client, endpointDescriptor, nodeDescriptor, browseParameters)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static UANodeElementCollection Browse( 
   IEasyUAClient client,
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor nodeDescriptor,
   UABrowseParameters browseParameters
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static UANodeElementCollection^ Browse( 
   IEasyUAClient^ client,
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ nodeDescriptor,
   UABrowseParameters^ browseParameters
)

Parameters

client: The client object that will perform the operation.
endpointDescriptor: UAEndpointDescriptor. Endpoint descriptor. Identifies the OPC-UA server.
nodeDescriptor: UANodeDescriptor. Node descriptor. Identifies the node in OPC server's address space.
browseParameters: UABrowseParameters. Specifies which nodes will be returned.

Return Value

The method returns a node element collection, which contains OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement values. Each element contains information about a particular node found.

Exceptions

Exception Description

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.
OpcLabs.EasyOpc.UA.OperationModel.UAException	The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

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.

OpcLabs.EasyOpc.UA.OperationModel.UAException

The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Example

// Shows how to obtain references of all kinds to nodes of all classes, from the "Server" node in the address space.

using System;
using System.Diagnostics;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class Browse
    {
        public static void All()
        {
            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 nodes under "Server" node
            UANodeElementCollection nodeElementCollection;
            try
            {
                nodeElementCollection = client.Browse(
                    endpointDescriptor,
                    UAObjectIds.Server,
                    new UABrowseParameters(UANodeClass.All, new[] { UAReferenceTypeIds.References }));
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Display results
            foreach (UANodeElement nodeElement in nodeElementCollection)
            {
                Debug.Assert(nodeElement != null);
                Console.WriteLine();
                Console.WriteLine("nodeElement.DisplayName: {0}", nodeElement.DisplayName);
                Console.WriteLine("nodeElement.NodeId: {0}", nodeElement.NodeId);
                Console.WriteLine("nodeElement.NodeId.ExpandedText: {0}", nodeElement.NodeId.ExpandedText);
            }
        }

        // Example output:
        //
        //nodeElement.DisplayName: ServerArray
        //nodeElement.NodeId: Server_ServerArray
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2254
        //
        //nodeElement.DisplayName: NamespaceArray
        //nodeElement.NodeId: Server_NamespaceArray
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2255
        //
        //nodeElement.DisplayName: ServerStatus
        //nodeElement.NodeId: Server_ServerStatus
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2256
        //
        //nodeElement.DisplayName: ServiceLevel
        //nodeElement.NodeId: Server_ServiceLevel
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2267
        //
        //nodeElement.DisplayName: Auditing
        //nodeElement.NodeId: Server_Auditing
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2994
        //
        //nodeElement.DisplayName: ServerCapabilities
        //nodeElement.NodeId: Server_ServerCapabilities
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2268
        //
        //nodeElement.DisplayName: ServerDiagnostics
        //nodeElement.NodeId: Server_ServerDiagnostics
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2274
        //
        //nodeElement.DisplayName: VendorServerInfo
        //nodeElement.NodeId: Server_VendorServerInfo
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2295
        //
        //nodeElement.DisplayName: ServerRedundancy
        //nodeElement.NodeId: Server_ServerRedundancy
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2296
        //
        //nodeElement.DisplayName: Namespaces
        //nodeElement.NodeId: Server_Namespaces
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=11715
        //
        //nodeElement.DisplayName: GetMonitoredItems
        //nodeElement.NodeId: Server_GetMonitoredItems
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=11492
        //
        //nodeElement.DisplayName: Data
        //nodeElement.NodeId: nsu=http://test.org/UA/Data/ ;ns=2;i=10157
        //nodeElement.NodeId.ExpandedText: nsu=http://test.org/UA/Data/ ;ns=2;i=10157
        //
        //nodeElement.DisplayName: Boilers
        //nodeElement.NodeId: nsu=http://opcfoundation.org/UA/Boiler/ ;ns=4;i=1240
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/Boiler/ ;ns=4;i=1240
        //
        //nodeElement.DisplayName: ServerType
        //nodeElement.NodeId: ServerType
        //nodeElement.NodeId.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2004
    }
}

# Shows how to obtain references of all kinds to nodes of all classes, from the "Server" node in the address space.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System.Collections.Generic import *
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.AddressSpace import *
from OpcLabs.EasyOpc.UA.AddressSpace.Standard 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/'

# Instantiate the client object.
client = EasyUAClient()

# Obtain nodes under "Server" node.
try:
    referenceTypeIdList = List[UANodeId]()
    referenceTypeIdList.Add(UAReferenceTypeIds.References)
    nodeElementCollection = IEasyUAClientExtension.Browse(client,
         endpointDescriptor,
         UANodeDescriptor(UAObjectIds.Server),
         UABrowseParameters(UANodeClass.All, referenceTypeIdList))
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for nodeElement in nodeElementCollection:
    assert nodeElement is not None
    print()
    print('nodeElement.DisplayName: ', nodeElement.DisplayName, sep='')
    print('nodeElement.NodeId: ', nodeElement.NodeId, sep='')
    print('nodeElement.NodeId.ExpandedText: ', nodeElement.NodeId.ExpandedText, sep='')

print()
print('Finished.')

' Shows how to obtain references of all kinds to nodes of all classes, from the "Server" node in the address space.

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Friend Class Browse
        Public Shared Sub All()

            ' 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 nodes under "Server" node
            Dim nodeElementCollection As UANodeElementCollection
            Try
                nodeElementCollection = client.Browse(
                    endpointDescriptor,
                    UAObjectIds.Server,
                    New UABrowseParameters(UANodeClass.All, New UANodeId() {UAReferenceTypeIds.References}))
                ' or "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each nodeElement As UANodeElement In nodeElementCollection
                Debug.Assert(nodeElement IsNot Nothing)
                Console.WriteLine()
                Console.WriteLine("nodeElement.NodeId: {0}", nodeElement.NodeId)
                Console.WriteLine("nodeElement.DisplayName: {0}", nodeElement.DisplayName)
            Next nodeElement
        End Sub
    End Class
End Namespace

CSharp
PowerShell
Python

// This example shows how to obtain nodes under a given node of the OPC-UA address space. 
// For each node, it displays its browse name and node ID.

using System;
using System.Diagnostics;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Navigation.Parsing;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class Browse
    {
        public static void Main1()
        {
            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/"

            var browsePathParser = new UABrowsePathParser("http://test.org/UA/Data/");
            UANodeDescriptor nodeDescriptor = browsePathParser.Parse("[ObjectsFolder]/Data/Static/UserScalar");

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

            // perform the operation
            UANodeElementCollection nodeElementCollection;
            try
            {
                nodeElementCollection = client.Browse(
                    endpointDescriptor, 
                    nodeDescriptor, 
                    UABrowseParameters.AllForwardReferences);
            }
            catch (UAException uaException)
            {
                Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
                return;
            }

            // Display results
            foreach (UANodeElement nodeElement in nodeElementCollection)
            {
                Debug.Assert(!(nodeElement is null));
                Console.WriteLine($"{nodeElement.BrowseName}: {nodeElement.NodeId}");
            }
        }

        // Example output:
        //
        //BooleanValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10384
        //SByteValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10385
        //ByteValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10386
        //Int16Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10387
        //UInt16Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10388
        //Int32Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10389
        //UInt32Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10390
        //Int64Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10391
        //UInt64Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10392
        //FloatValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10393
        //DoubleValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10394
        //StringValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10395
        //DateTimeValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10396
        //GuidValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10397
        //ByteStringValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10398
        //XmlElementValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10399
        //NodeIdValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10400
        //ExpandedNodeIdValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10401
        //QualifiedNameValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10402
        //LocalizedTextValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10403
        //StatusCodeValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10404
        //VariantValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10405
        //SimulationActive: nsu=http://test.org/UA/Data/ ;ns=2;i=10328
        //GenerateValues: nsu=http://test.org/UA/Data/ ;ns=2;i=10329
        //CycleComplete: nsu=http://test.org/UA/Data/ ;ns=2;i=10331
        //UserScalarValueObjectType: nsu=http://test.org/UA/Data/ ;ns=2;i=9921
    }
}

# This example shows how to obtain nodes under a given node of the OPC-UA address space. 
# For each node, it displays its browse name and node ID.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.Navigation.Parsing;
using namespace OpcLabs.EasyOpc.UA.OperationModel

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUA.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUAComponents.dll"

[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/"

$browsePathParser = New-Object UABrowsePathParser("http://test.org/UA/Data/")
$nodeDescriptor = $browsePathParser.Parse("[ObjectsFolder]/Data/Static/UserScalar")

# Instantiate the client object.
$client = New-Object EasyUAClient

# perform the operation
try {
$nodeElementCollection = [IEasyUAClientExtension]::Browse($client,
    $endpointDescriptor, 
    $nodeDescriptor, 
    [UABrowseParameters]::AllForwardReferences)
}
catch [UAException] {
    Write-Host "*** Failure: $($PSItem.Exception.GetBaseException().Message)"
    return
}

# Display results
foreach ($nodeElement in $nodeElementCollection) {
    Write-Host "$($nodeElement.BrowseName): $($nodeElement.NodeId)"
}


# Example output:
#
#BooleanValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10384
#SByteValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10385
#ByteValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10386
#Int16Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10387
#UInt16Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10388
#Int32Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10389
#UInt32Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10390
#Int64Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10391
#UInt64Value: nsu=http://test.org/UA/Data/ ;ns=2;i=10392
#FloatValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10393
#DoubleValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10394
#StringValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10395
#DateTimeValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10396
#GuidValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10397
#ByteStringValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10398
#XmlElementValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10399
#NodeIdValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10400
#ExpandedNodeIdValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10401
#QualifiedNameValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10402
#LocalizedTextValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10403
#StatusCodeValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10404
#VariantValue: nsu=http://test.org/UA/Data/ ;ns=2;i=10405
#SimulationActive: nsu=http://test.org/UA/Data/ ;ns=2;i=10328
#GenerateValues: nsu=http://test.org/UA/Data/ ;ns=2;i=10329
#CycleComplete: nsu=http://test.org/UA/Data/ ;ns=2;i=10331
#UserScalarValueObjectType: nsu=http://test.org/UA/Data/ ;ns=2;i=9921

# This example shows how to obtain nodes under a given node of the OPC-UA address space. 
# For each node, it displays its browse name and node ID.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Navigation.Parsing 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/'

browsePathParser = UABrowsePathParser('http://test.org/UA/Data/')
nodeDescriptor = UANodeDescriptor(browsePathParser.Parse('[ObjectsFolder]/Data/Static/UserScalar'))

# Instantiate the client object.
client = EasyUAClient()

# Perform the operation.
try:
    nodeElements = IEasyUAClientExtension.Browse(client,
         endpointDescriptor,
         nodeDescriptor,
         UABrowseParameters.AllForwardReferences)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for nodeElement in nodeElements:
    assert nodeElement is not None
    print(nodeElement.BrowseName, ': ', nodeElement.NodeId, sep='')

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

IEasyUAClientExtension Class
IEasyUAClientExtension Members
Overload List

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