WriteList Method (_EasyUAClient)

Writes data into multiple attributes, using array of argument objects as an input.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<JetBrains.Annotations.NotNullAttribute()>
Function WriteList( _
   ByVal writeArgumentsList As IList _
) As _ElasticVector

'Usage
 
Dim instance As _EasyUAClient
Dim writeArgumentsList As IList
Dim value As _ElasticVector
 
value = instance.WriteList(writeArgumentsList)

[JetBrains.Annotations.NotNull()]
_ElasticVector WriteList( 
   IList writeArgumentsList
)

[JetBrains.Annotations.NotNull()]
_ElasticVector^ WriteList( 
   IList^ writeArgumentsList
)

Parameters

writeArgumentsList

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

Return Value

Array of OpcLabs.EasyOpc.UA.OperationModel.UAWriteResult. The method returns an array of OpcLabs.EasyOpc.UA.OperationModel.UAWriteResult objects. The indices of elements in the output array are the same as those in the input arrays.

This method never returns null (Nothing in Visual Basic).

The individual elements of the returned value are never null (Nothing in Visual Basic).

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.
System.ObjectDisposedException	An operation was performed on a disposed object.

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.

System.ObjectDisposedException An operation was performed on a disposed object.

Remarks

This method uses lists instead of arrays.

This member is not compatible with VBScript.

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

Example

CSharp
VB.NET
Python

// This example shows how to write data (a value, timestamps and status code) into 3 nodes at once, test for success of each 
// write and display the exception message in case of failure.
//
// 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.OperationModel;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    class WriteMultiple
    {
        public static void TestSuccess()
        {
            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();

            // Modify data of nodes' attributes
            OperationResult[] operationResultArray = client.WriteMultiple(new[]
                {
                    new UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10221", 
                        new UAAttributeData(23456, UASeverity.GoodOrSuccess, DateTime.UtcNow)),
                    new UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10226", 
                        new UAAttributeData(2.34567890, UASeverity.GoodOrSuccess, DateTime.UtcNow)),
                    new UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10227", 
                        new UAAttributeData("ABC", UASeverity.GoodOrSuccess, DateTime.UtcNow))
                });

            // The target server may not support this, and in such case failures will occur.

            for (int i = 0; i < operationResultArray.Length; i++)
                if (operationResultArray[i].Succeeded)
                    Console.WriteLine("Result {0}: success", i);
                else
                    Console.WriteLine("Result {0}: {1}", i, operationResultArray[i].Exception.GetBaseException().Message);
        }
    }
}

' This example shows how to write data (a value, timestamps and status code) into 3 nodes at once, test for success of each 
' write and display the exception message in case of failure.
'
' 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.OperationModel
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Friend Class WriteMultiple
        Public Shared Sub TestSuccess()

            ' 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()

            ' Modify data of nodes' attributes
            Dim operationResultArray() As OperationResult = client.WriteMultiple(New UAWriteArguments() _
              {
                  New UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10221",
                                       New UAAttributeData(23456, UASeverity.GoodOrSuccess, Date.UtcNow)),
                  New UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10226",
                                       New UAAttributeData(2.3456789, UASeverity.GoodOrSuccess, Date.UtcNow)),
                  New UAWriteArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10227",
                                       New UAAttributeData("ABC", UASeverity.GoodOrSuccess, Date.UtcNow))
              }
            )

            ' The target server may not support this, and in such case failures will occur.

            For i As Integer = 0 To operationResultArray.Length - 1
                If operationResultArray(i).Succeeded Then
                    Console.WriteLine("Result {0}: success", i)
                Else
                    Console.WriteLine("Result {0}: {1}", i, operationResultArray(i).Exception.GetBaseException().Message)
                End If
            Next i
        End Sub
    End Class
End Namespace

# This example shows how to write data (a value, timestamps and status code) into 3 nodes at once, test for success of
# each write and display the exception message in case of failure.
#
# 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.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/'

# Instantiate the client object
client = EasyUAClient()

print("Modifying data of nodes' attributes...")
writeResultArray = client.WriteMultiple([
    UAWriteArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10221'),
                     UAAttributeData(23456, UAStatusCode(UASeverity.GoodOrSuccess), DateTime.UtcNow)),
    UAWriteArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10226'),
                     UAAttributeData(2.34567890, UAStatusCode(UASeverity.GoodOrSuccess), DateTime.UtcNow)),
    UAWriteArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10227'),
                     UAAttributeData('ABC', UAStatusCode(UASeverity.GoodOrSuccess), DateTime.UtcNow)),
    ])

# The target server may not support this, and in such case failures will occur.
for i, writeResult in enumerate(writeResultArray):
    if writeResult.Succeeded:
        print('writeResultArray[', i, ']: success', sep='')
    else:
        print('writeResultArray[', i, '] *** Failure: ', writeResult.Exception.GetBaseException().Message, sep='')

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

Reference

_EasyUAClient Interface
_EasyUAClient Members
ReadMultiple Method

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