OPC Studio User's Guide and Reference
WriteMultipleItems Method (_EasyDAClient)
Example 



OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.DataAccess.ComTypes Namespace > _EasyDAClient Interface : WriteMultipleItems Method
Array of argument objects for the operation.
Writes named items into an OPC server or OPC servers. Values, qualities and timestamps are written.
Syntax
'Declaration
 
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Function WriteMultipleItems( _
   ByVal argumentsArray As Object _
) As Object()
'Usage
 
Dim instance As _EasyDAClient
Dim argumentsArray As Object
Dim value() As Object
 
value = instance.WriteMultipleItems(argumentsArray)
[ElementsNotNull()]
[NotNull()]
object[] WriteMultipleItems( 
   object argumentsArray
)
[ElementsNotNull()]
[NotNull()]
array<Object^>^ WriteMultipleItems( 
   Object^ 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
ExceptionDescription

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.

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

.NET

COM

// This example shows how to write values, timestamps and qualities into 3 items at once.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

#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/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassicCore.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassic.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassicComponents.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)"
    }
}
# This example shows how to write values, timestamps and qualities into 3 items 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 .
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from System import *
from OpcLabs.EasyOpc import *
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.DataAccess.OperationModel import *
from OpcLabs.EasyOpc.OperationModel import *


# Instantiate the client object.
client = EasyDAClient()

print('Writing multiple items...')
operationResultArray = client.WriteMultipleItems([
    DAItemVtqArguments(ServerDescriptor('OPCLabs.KitServer.2'), DAItemDescriptor('Simulation.Register_I4'),
                       DAVtq(23456, DateTime.UtcNow, DAQuality(DAQualities.GoodNonspecific))),
    DAItemVtqArguments(ServerDescriptor('OPCLabs.KitServer.2'), DAItemDescriptor('Simulation.Register_R8'),
                       DAVtq(2.34567890, DateTime.UtcNow, DAQuality(DAQualities.GoodNonspecific))),
    DAItemVtqArguments(ServerDescriptor('OPCLabs.KitServer.2'), DAItemDescriptor('Simulation.Register_BSTR'),
                       DAVtq('ABC', DateTime.UtcNow, DAQuality(DAQualities.GoodNonspecific))),
    ])

for i, operationResult in enumerate(operationResultArray):
    assert operationResult is not None
    if operationResult.Succeeded:
        print('operationResultArray[', i, ']: success', sep='')
    else:
        assert operationResult.Exception is not None
        print('operationResultArray[', i, '] *** Failure: ', operationResult.ErrorMessageBrief, sep='')

print('Finished.')
' This example shows how to write values, timestamps and qualities into 3 items at once.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports OpcLabs.BaseLib.OperationModel
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.OperationModel

Namespace DataAccess._EasyDAClient
    Partial Friend Class WriteMultipleItems
        Public Shared Sub Main1()
            ' Instantiate the client object.
            Dim client = New EasyDAClient()

            Console.WriteLine("Writing multiple items...")
            Dim resultArray() As OperationResult = client.WriteMultipleItems(New DAItemVtqArguments() {
                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(2.3456789, DateTime.UtcNow, DAQualities.GoodNonspecific)),
                New DAItemVtqArguments("OPCLabs.KitServer.2", "Simulation.Register_BSTR",
                    New DAVtq("ABC", DateTime.UtcNow, DAQualities.GoodNonspecific))
            })

            For i = 0 To resultArray.Length - 1
                Debug.Assert(resultArray(i) IsNot Nothing)

                If resultArray(i).Succeeded Then
                    Console.WriteLine("Result {0}: success", i)
                Else
                    Debug.Assert(resultArray(i).Exception IsNot Nothing)
                    Console.WriteLine("Result {0} *** Failure: {1}", i, resultArray(i).ErrorMessageBrief)
                End If
            Next i
        End Sub
    End Class
End Namespace
// This example shows how to write values, timestamps and qualities into 3 items at once.
//
// Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

class procedure WriteMultipleItems.Main;
var
  Arguments: OleVariant;
  Client: OpcLabs_EasyOpcClassic_TLB._EasyDAClient;
  I: Cardinal;
  ItemVtqArguments1: _DAItemVtqArguments;
  ItemVtqArguments2: _DAItemVtqArguments;
  ItemVtqArguments3: _DAItemVtqArguments;
  Results: OleVariant;
  OperationResult: _OperationResult;

begin
  ItemVtqArguments1 := CoDAItemVtqArguments.Create;
  ItemVtqArguments1.ServerDescriptor.ServerClass := 'OPCLabs.KitServer.2';
  ItemVtqArguments1.ItemDescriptor.ItemID := 'Simulation.Register_I4';
  ItemVtqArguments1.Vtq.Value := 23456;
  ItemVtqArguments1.Vtq.TimestampLocal := Now();
  ItemVtqArguments1.Vtq.Quality.NumericalValue := DAQualities_GoodNonSpecific;

  ItemVtqArguments2 := CoDAItemVtqArguments.Create;
  ItemVtqArguments2.ServerDescriptor.ServerClass := 'OPCLabs.KitServer.2';
  ItemVtqArguments2.ItemDescriptor.ItemID := 'Simulation.Register_R8';
  ItemVtqArguments2.Vtq.Value := 2.34567890;
  ItemVtqArguments2.Vtq.TimestampLocal := Now();
  ItemVtqArguments2.Vtq.Quality.NumericalValue := DAQualities_GoodNonSpecific;

  ItemVtqArguments3 := CoDAItemVtqArguments.Create;
  ItemVtqArguments3.ServerDescriptor.ServerClass := 'OPCLabs.KitServer.2';
  ItemVtqArguments3.ItemDescriptor.ItemID := 'Simulation.Register_BSTR';
  ItemVtqArguments3.Vtq.Value := 'ABC';
  ItemVtqArguments3.Vtq.TimestampLocal := Now();
  ItemVtqArguments3.Vtq.Quality.NumericalValue := DAQualities_GoodNonSpecific;

  Arguments := VarArrayCreate([0, 2], varVariant);
  Arguments[0] := ItemVtqArguments1;
  Arguments[1] := ItemVtqArguments2;
  Arguments[2] := ItemVtqArguments3;

  // Instantiate the client object
  Client := CoEasyDAClient.Create;

  // Modify values of nodes
  TVarData(Results).VType := varArray or varVariant;
  TVarData(Results).VArray := PVarArray(
    Client.WriteMultipleItems(Arguments));

  // Display results
  for I := VarArrayLowBound(Results, 1) to VarArrayHighBound(Results, 1) do
  begin
    OperationResult := IInterface(Results[I]) as _OperationResult;
    if OperationResult.Succeeded then
      WriteLn('Result ', I, ' success')
    else
      WriteLn('Result ', I, ' *** Failure: ', OperationResult.Exception.GetBaseException.Message);
  end;

  VarClear(Results);
  VarClear(Arguments);
end;
REM This example shows how to write values, timestamps and qualities into 3 items at once.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Private Sub WriteMultipleItems_Main_Command_Click()
    OutputText = ""
    
    Dim itemVtqArguments1 As New DAItemVtqArguments
    itemVtqArguments1.serverDescriptor.ServerClass = "OPCLabs.KitServer.2"
    itemVtqArguments1.ItemDescriptor.itemId = "Simulation.Register_I4"
    itemVtqArguments1.vtq.SetValue 23456
    itemVtqArguments1.vtq.TimestampLocal = Now()
    itemVtqArguments1.vtq.Quality.NumericalValue = DAQualities_GoodNonspecific
    
    Dim itemVtqArguments2 As New DAItemVtqArguments
    itemVtqArguments2.serverDescriptor.ServerClass = "OPCLabs.KitServer.2"
    itemVtqArguments2.ItemDescriptor.itemId = "Simulation.Register_R8"
    itemVtqArguments2.vtq.SetValue 2.3456789
    itemVtqArguments2.vtq.TimestampLocal = Now()
    itemVtqArguments2.vtq.Quality.NumericalValue = DAQualities_GoodNonspecific
    
    Dim itemVtqArguments3 As New DAItemVtqArguments
    itemVtqArguments3.serverDescriptor.ServerClass = "OPCLabs.KitServer.2"
    itemVtqArguments3.ItemDescriptor.itemId = "Simulation.Register_BSTR"
    itemVtqArguments3.vtq.SetValue "ABC"
    itemVtqArguments3.vtq.TimestampLocal = Now()
    itemVtqArguments3.vtq.Quality.NumericalValue = DAQualities_GoodNonspecific
    
    Dim arguments(2) As Variant
    Set arguments(0) = itemVtqArguments1
    Set arguments(1) = itemVtqArguments2
    Set arguments(2) = itemVtqArguments3

    ' Instantiate the client object
    Dim client As New EasyDAClient

    ' Modify values of nodes
    Dim results() As Variant
    results = client.WriteMultipleItems(arguments)

    ' Display results
    Dim i: For i = LBound(results) To UBound(results)
        Dim operationResult As operationResult: Set operationResult = results(i)
        If operationResult.Succeeded Then
            OutputText = OutputText & "result " & i & " success" & vbCrLf
        Else
            OutputText = OutputText & "result " & i & " *** Failure: " & operationResult.ErrorMessageBrief & vbCrLf
        End If
    Next
End Sub
Rem This example shows how to write values, timestamps and qualities into 3 items at once.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Dim ItemVtqArguments1: Set ItemVtqArguments1 = CreateObject("OpcLabs.EasyOpc.DataAccess.OperationModel.DAItemVtqArguments")
ItemVtqArguments1.ServerDescriptor.ServerClass = "OPCLabs.KitServer.2"
ItemVtqArguments1.ItemDescriptor.ItemID = "Simulation.Register_I4"
ItemVtqArguments1.Vtq.Value = 23456
ItemVtqArguments1.Vtq.TimestampLocal = Now()
ItemVtqArguments1.Vtq.Quality.NumericalValue = 192

Dim ItemVtqArguments2: Set ItemVtqArguments2 = CreateObject("OpcLabs.EasyOpc.DataAccess.OperationModel.DAItemVtqArguments")
ItemVtqArguments2.ServerDescriptor.ServerClass = "OPCLabs.KitServer.2"
ItemVtqArguments2.ItemDescriptor.ItemID = "Simulation.Register_R8"
ItemVtqArguments2.Vtq.Value = 2.34567890
ItemVtqArguments2.Vtq.TimestampLocal = Now()
ItemVtqArguments2.Vtq.Quality.NumericalValue = 192

Dim ItemVtqArguments3: Set ItemVtqArguments3 = CreateObject("OpcLabs.EasyOpc.DataAccess.OperationModel.DAItemVtqArguments")
ItemVtqArguments3.ServerDescriptor.ServerClass = "OPCLabs.KitServer.2"
ItemVtqArguments3.ItemDescriptor.ItemID = "Simulation.Register_BSTR"
ItemVtqArguments3.Vtq.Value = "ABC"
ItemVtqArguments3.Vtq.TimestampLocal = Now()
ItemVtqArguments3.Vtq.Quality.NumericalValue = 192

Dim arguments(2)
Set arguments(0) = ItemVtqArguments1
Set arguments(1) = ItemVtqArguments2
Set arguments(2) = ItemVtqArguments3

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
Dim results: results = Client.WriteMultipleItems(arguments)

Dim i: For i = LBound(results) To UBound(results)
    Dim OperationResult: Set OperationResult = results(i)
    If OperationResult.Succeeded Then
        WScript.Echo "Result " & i & ": success"
    Else
        WScript.Echo "Result " & i & ": " & OperationResult.Exception.GetBaseException.Message
    End If
Next
Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also