OPC Studio User's Guide and Reference
Examples - OPC Unified Architecture - Write multiple values
View with Navigation Tools

Example 1:

.NET

// This example shows how to write values into 3 nodes at once.
//
// 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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class WriteMultipleValues
    {
        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/"

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

            // Modify value of a node
            client.WriteMultipleValues(new[]
                {
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10221", 23456),
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10226", 2.34567890),
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10227", "ABC")
                });
            // Production code would check the success of the operation. See separate example for that.
        }
    }
}

Python

# This example shows how to write values into 3 nodes at once.
#
# 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 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 values of nodes...')
writeResultArray = IEasyUAClientExtension.WriteMultipleValues(client, [
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10221'), 23456),
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10226'), 2.34567890),
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10227'), 'ABC'),
    ])

# Production code would check the success of the operation. See separate example for that.

print()
print('Finished.')

Example 2:

The example above can be extended by properly testing for success of each operation, like this:

.NET

// This example shows how to write values 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
{
    partial class WriteMultipleValues
    {
        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();

            Console.WriteLine("Modifying values of nodes...");
            OperationResult[] operationResultArray = client.WriteMultipleValues(new[]
                {
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10221", 23456),
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10226", 
                        "This string cannot be converted to Double"),
                    new UAWriteValueArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;s=UnknownNode", "ABC")
                });

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


            // Example output:
            //
            //Modifying values of nodes...
            //Result 0: success
            //Result 1: Input string was not in a correct format.
            //+ Attempting to change an object of type "System.String" to type "System.Double".
            //+ The specified original value (string) was "This string cannot be converted to Double".
            //+ The node descriptor used was: NodeId="nsu=http://test.org/UA/Data/ ;i=10226".
            //+ The client method called (or event/callback invoked) was 'WriteMultiple[3]'.
            //Result 2: The status of the OPC-UA attribute data is not Good. The actual status is 'BadNodeIdUnknown'.
            //+ During writing or method calls, readings may occur when value type is not specified.
            //+ The node descriptor used was: NodeId="nsu=http://test.org/UA/Data/ ;s=UnknownNode".
            //+ The client method called (or event/callback invoked) was 'WriteMultiple[3]'.
        }
    }
}

COM

// This example shows how to write values 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 .
// 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.

#include "stdafx.h"    // Includes "QuickOpc.h", and other commonly used files
#include <atlsafe.h>
#include "WriteMultipleValues.h"

namespace _EasyUAClient
{
    void WriteMultipleValues::TestSuccess()
    {
        // Initialize the COM library
        CoInitializeEx(NULL, COINIT_MULTITHREADED);
        {
            // Instantiate the client object
            _EasyUAClientPtr ClientPtr(__uuidof(EasyUAClient));

            _UAWriteValueArgumentsPtr WriteValueArguments1Ptr(_uuidof(UAWriteValueArguments));
            WriteValueArguments1Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            WriteValueArguments1Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10221";
            WriteValueArguments1Ptr->Value = 23456;

            _UAWriteValueArgumentsPtr WriteValueArguments2Ptr(_uuidof(UAWriteValueArguments));
            WriteValueArguments2Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            WriteValueArguments2Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10226";
            WriteValueArguments2Ptr->Value = L"This string cannot be converted to Double";

            _UAWriteValueArgumentsPtr WriteValueArguments3Ptr(_uuidof(UAWriteValueArguments));
            WriteValueArguments3Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            WriteValueArguments3Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;s=UnknownNode";
            WriteValueArguments3Ptr->Value = L"ABC";

            CComSafeArray<VARIANT> arguments(3);
            arguments.SetAt(0, _variant_t((IDispatch*)WriteValueArguments1Ptr));
            arguments.SetAt(1, _variant_t((IDispatch*)WriteValueArguments2Ptr));
            arguments.SetAt(2, _variant_t((IDispatch*)WriteValueArguments3Ptr));
            CComVariant vArguments(arguments);

            // Obtain values. By default, the Value attributes of the nodes will be Write.
            CComSafeArray<VARIANT> results;
            results.Attach(ClientPtr->WriteMultipleValues(&vArguments));
            
            // Display results
            for (int i = results.GetLowerBound(); i <= results.GetUpperBound(); i++)
            {
                _UAWriteResultPtr ResultPtr = results[i];

                if (ResultPtr->Succeeded)
                    _tprintf(_T("Result %d success\n"), i);
                else
                    _tprintf(_T("Result d: s\n"), i, (LPCTSTR)CW2CT(ResultPtr->Exception->GetBaseException()->Message));
            }
        }
         // Release all interface pointers BEFORE calling CoUninitialize()
        CoUninitialize();
    }
}

Python

# This example shows how to write values 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 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 values of nodes...')
writeResultArray = IEasyUAClientExtension.WriteMultipleValues(client, [
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10221'), 23456),
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10226'),
                          'This string cannot be converted to Double'),
    UAWriteValueArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;s=UnknownNode'), 'ABC'),
    ])

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.')

 

See Also

Concepts

Examples - Client OPC Data Access