WriteMultiple Method (IEasyUAClient)

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

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<NotNullAttribute()>
Function WriteMultiple( _
   ByVal writeArgumentsArray() As UAWriteArguments _
) As UAWriteResult()

'Usage
 
Dim instance As IEasyUAClient
Dim writeArgumentsArray() As UAWriteArguments
Dim value() As UAWriteResult
 
value = instance.WriteMultiple(writeArgumentsArray)

[NotNull()]
UAWriteResult[] WriteMultiple( 
   UAWriteArguments[] writeArgumentsArray
)

[NotNull()]
array<UAWriteResult^>^ WriteMultiple( 
   array<UAWriteArguments^>^ writeArgumentsArray
)

Parameters

writeArgumentsArray

Array of OpcLabs.EasyOpc.UA.OperationModel.UAWriteArguments. Array of argument objects specifying what to write from an OPC-UA server.

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).

This is a multiple-operation method. In a properly written program, it does not throw any exceptions. You should therefore not put try/catch statements or similar constructs around calls to this method. The only exceptions thrown by this method are for usage errors, i.e. when your code violates the usage contract of the method, such as passing in invalid arguments or calling the method when the state of the object does not allow it. Any operation-related errors (i.e. errors that depend on external conditions that your code cannot reliably check) are indicated in the result objects returned by the method. For more information, see Multiple-operation Methods and Do not catch any exceptions with asynchronous or multiple-operation methods.

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.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.

Remarks

The size of the input array will become the size of the output array. The element positions (indices) in the output array are the same as in the input array.

This method does not throw an exception in case of OPC operation failures. Instead, the eventual exception related to each item is returned in OpcLabs.BaseLib.OperationModel.OperationResult.Exception> property of each returned OpcLabs.EasyOpc.UA.OperationModel.UAWriteResult element.

Each element in the input array corresponds to a separate logical write operation (although the operations may and will be executed together, if possible). The method returns an array of results, where each result corresponds to the write operation at the same index in the input array.

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

IEasyUAClient Interface
IEasyUAClient Members
ReadMultiple Method

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