WriteMultipleItems Method (EasyDAClient)

Writes named items into an OPC server or OPC servers. Values, qualities and timestamps are written.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Function WriteMultipleItems( _
   ByVal argumentsArray() As DAItemVtqArguments _
) As OperationResult()

'Usage
 
Dim instance As EasyDAClient
Dim argumentsArray() As DAItemVtqArguments
Dim value() As OperationResult
 
value = instance.WriteMultipleItems(argumentsArray)

public OperationResult[] WriteMultipleItems( 
   DAItemVtqArguments[] argumentsArray
)

public:
array<OperationResult^>^ WriteMultipleItems( 
   array<DAItemVtqArguments^>^ argumentsArray
)

Parameters

argumentsArray: Array of argument objects for the operation.

Return Value

The function returns an array of OpcLabs.BaseLib.OperationModel.OperationResult objects. The indices of elements in the output array are the same as those in the input arrays.

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.

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.

The servers can be local or can be remotely accessed via DCOM. Optionally, an access path can be specified or a specific data type can be requested.

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

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.

Example

CSharp
PowerShell

// This example shows how to write values, timestamps and qualities into 3 items at once.

using System;
using System.Diagnostics;
using OpcLabs.BaseLib.OperationModel;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.OperationModel;

namespace DocExamples.DataAccess._EasyDAClient
{
    class WriteMultipleItems
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            Console.WriteLine("Writing multiple items...");
            OperationResult[] resultArray = client.WriteMultipleItems(
                new[] { 
                    new DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_I4", 
                        new DAVtq(23456, DateTime.UtcNow, DAQualities.GoodNonspecific)),
                    new DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_R8", 
                        new DAVtq(2.34567890, DateTime.UtcNow, DAQualities.GoodNonspecific)),
                    new DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_BSTR", 
                        new DAVtq("ABC", DateTime.UtcNow, DAQualities.GoodNonspecific))
                });
            
            for (int i = 0; i < resultArray.Length; i++)
            {
                Debug.Assert(resultArray[i] != null);
                if (resultArray[i].Succeeded)
                    Console.WriteLine("Result {0}: success", i);
                else
                {
                    Debug.Assert(!(resultArray[i].Exception is null));
                    Console.WriteLine("Result {0} *** Failure: {1}", i, resultArray[i].ErrorMessageBrief);
                }
            }
        }
    }
}

# This example shows how to write values, timestamps and qualities into 3 items at once.

#requires -Version 5.1
using namespace System
using namespace OpcLabs.EasyOpc.DataAccess
using namespace OpcLabs.EasyOpc.DataAccess.OperationModel

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

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

Write-Host "Writing multiple items..."
$resultArray = $client.WriteMultipleItems(@(
    (New-Object DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_I4", 
        (New-Object DAVtq(23456, [DateTime]::UtcNow, [DAQualities]::GoodNonspecific)))),
    (New-Object DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_R8", 
        (New-Object DAVtq(2.345667890, [DateTime]::UtcNow, [DAQualities]::GoodNonspecific)))),
    (New-Object DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_BSTR",
        (New-Object DAVtq("ABC", [DateTime]::UtcNow, [DAQualities]::GoodNonspecific))))
    ))

for ($i = 0; $i -lt $resultArray.Length; $i++) {
    $result = $resultArray[$i]
    if ($result.Succeeded) {
        Write-Host "Result $($i): success"
    }
    else {
        Write-Host "Result $($i) *** Failure: $($result.ErrorMessageBrief)"
    }
}

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012 R2, Windows Server 2016; .NET: Linux, macOS, Microsoft Windows

Reference

EasyDAClient Class
EasyDAClient Members

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