GetMonitoredItemArguments Method (EasyUAClientCore)

Obtains parameters of certain monitored item subscription.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Function GetMonitoredItemArguments( _
   ByVal handle As Integer _
) As EasyUAMonitoredItemArguments

'Usage
 
Dim instance As EasyUAClientCore
Dim handle As Integer
Dim value As EasyUAMonitoredItemArguments
 
value = instance.GetMonitoredItemArguments(handle)

public EasyUAMonitoredItemArguments GetMonitoredItemArguments( 
   int handle
)

public:
EasyUAMonitoredItemArguments^ GetMonitoredItemArguments( 
   int handle
)

Parameters

handle: Monitored item subscription handle as returned by the subscription method.

Return Value

Returns an object that holds all information pertaining to the monitored item subscription: attribute information, subscription parameters, and monitoring parameters.

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

Exceptions

Exception	Description
System.ArgumentException	One of the arguments provided to a method is not valid. 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.

Exception

Description

System.ArgumentException

One of the arguments provided to a method is not valid.

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.

Example

CSharp
PowerShell
VB.NET
Object Pascal
Python

// This example shows how to obtain parameters of certain monitored item subscription.
//
// 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.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    class GetMonitoredItemArguments
    {
        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 and hook events.
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification;

            Console.WriteLine("Subscribing...");
            int[] handleArray = client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10845", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10853", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10855", 1000)
                });

            Console.WriteLine("Getting monitored item arguments...");
            EasyUAMonitoredItemArguments monitoredItemArguments =
                client.GetMonitoredItemArguments(handleArray[2]);
            Console.WriteLine($"NodeDescriptor: {monitoredItemArguments.NodeDescriptor}");
            Console.WriteLine($"SamplingInterval: {monitoredItemArguments.MonitoringParameters.SamplingInterval}");
            Console.WriteLine($"PublishingInterval: {monitoredItemArguments.SubscriptionParameters.PublishingInterval}");

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }

        static void client_DataChangeNotification(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Your code would do the processing here.
        }


        // Example output:
        //
        //Subscribing...
        //Getting monitored item arguments...
        //NodeDescriptor: NodeId="nsu=http://test.org/UA/Data/ ;i=10855"
        //SamplingInterval: 1000
        //PublishingInterval: 0
        //Waiting for 5 seconds...
        //Unsubscribing...
        //Waiting for 5 seconds...
        //Finished.

    }
}

# This example shows how to obtain parameters of certain monitored item subscription.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PowerShell .
# 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.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.OperationModel

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

[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.
$client = New-Object EasyUAClient

# Data change notification handler
Register-ObjectEvent -InputObject $client -EventName DataChangeNotification -Action { 
    # Your code would do the processing here.
}

Write-Host "Subscribing..."
$handleArray = $client.SubscribeMultipleMonitoredItems(@(
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10845")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10853")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10855")),
        1000))
    ))

Write-Host "Getting monitored item arguments..."
$monitoredItemArguments = $client.GetMonitoredItemArguments($handleArray[2])
Write-Host "NodeDescriptor: $($monitoredItemArguments.NodeDescriptor)"
Write-Host "SamplingInterval: $($monitoredItemArguments.MonitoringParameters.SamplingInterval)"
Write-Host "PublishingInterval: $($monitoredItemArguments.SubscriptionParameters.PublishingInterval)"

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Unsubscribing..."
$client.UnsubscribeAllMonitoredItems()

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Finished."


# Example output:
#
#Subscribing...
#Getting monitored item arguments...
#NodeDescriptor: NodeId="nsu=http://test.org/UA/Data/ ;i=10855"
#SamplingInterval: 1000
#PublishingInterval: 0
#Waiting for 5 seconds...
#Unsubscribing...
#Waiting for 5 seconds...
#Finished.

' This example shows how to obtain parameters of certain monitored item subscription.
'
' 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 OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Friend Class GetMonitoredItemArguments
        Public Shared Sub Main1()

            ' 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 and hook events
            Dim client = New EasyUAClient()
            AddHandler client.DataChangeNotification, AddressOf client_DataChangeNotification

            Console.WriteLine("Subscribing...")
            Dim handleArray() As Integer = client.SubscribeMultipleMonitoredItems(New EasyUAMonitoredItemArguments() _
               { _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845", 1000), _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000), _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855", 1000) _
               } _
            )

            Console.WriteLine("Getting monitored item arguments...")
            Dim monitoredItemArguments As EasyUAMonitoredItemArguments = client.GetMonitoredItemArguments(handleArray(2))
            Console.WriteLine("NodeDescriptor: {0}", monitoredItemArguments.NodeDescriptor)
            Console.WriteLine("SamplingInterval: {0}", monitoredItemArguments.MonitoringParameters.SamplingInterval)
            Console.WriteLine("PublishingInterval: {0}", monitoredItemArguments.SubscriptionParameters.PublishingInterval)

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)

            Console.WriteLine("Unsubscribing...")
            client.UnsubscribeAllMonitoredItems()

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_DataChangeNotification(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs)
            ' Your code would do the processing here
        End Sub
    End Class
End Namespace

// This example shows how to obtain parameters of certain monitored item subscription.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// 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.

type
  TClientEventHandlers115 = class
    procedure Client_DataChangeNotification(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataChangeNotificationEventArgs);
  end;

procedure TClientEventHandlers115.Client_DataChangeNotification(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataChangeNotificationEventArgs);
begin
  // Your code would do the processing here
end;

class procedure GetMonitoredItemArguments.Main;
var
  Arguments: OleVariant;
  Client: TEasyUAClient;
  ClientEventHandlers: TClientEventHandlers115;
  HandleArray: OleVariant;
  MonitoredItemArguments1, MonitoredItemArguments2, MonitoredItemArguments3:
    _EasyUAMonitoredItemArguments;
  MonitoredItemArguments: _EasyUAMonitoredItemArguments;
begin
  // Instantiate the client object and hook events
  Client := TEasyUAClient.Create(nil);
  ClientEventHandlers := TClientEventHandlers115.Create;
  Client.OnDataChangeNotification := ClientEventHandlers.Client_DataChangeNotification;

  WriteLn('Subscribing...');
  MonitoredItemArguments1 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments1.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  MonitoredItemArguments1.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10845';
  MonitoredItemArguments2 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments2.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  MonitoredItemArguments2.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10853';
  MonitoredItemArguments3 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments3.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  MonitoredItemArguments3.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10855';

  Arguments := VarArrayCreate([0, 2], varVariant);
  Arguments[0] := MonitoredItemArguments1;
  Arguments[1] := MonitoredItemArguments2;
  Arguments[2] := MonitoredItemArguments3;

  TVarData(HandleArray).VType := varArray or varVariant;
  TVarData(HandleArray).VArray := PVarArray(
    Client.SubscribeMultipleMonitoredItems(Arguments));

  WriteLn('Getting monitored item arguments...');
  MonitoredItemArguments := Client.GetMonitoredItemArguments(HandleArray[2]);

  WriteLn('NodeDescriptor: ', MonitoredItemArguments.NodeDescriptor.ToString);
  WriteLn('SamplingInterval: ', MonitoredItemArguments.MonitoringParameters.ToString);
  WriteLn('PublishingInterval: ', MonitoredItemArguments.SubscriptionParameters.ToString);

  WriteLn('Waiting for 5 seconds...');
  PumpSleep(5*1000);

  WriteLn('Unsubscribing...');
  Client.UnsubscribeAllMonitoredItems;

  WriteLn('Waiting for 5 seconds...');
  Sleep(5*1000);

  WriteLn('Finished.');
  
  VarClear(HandleArray);
  VarClear(Arguments);
  FreeAndNil(Client);
  FreeAndNil(ClientEventHandlers);
end;

# This example shows how to obtain parameters of certain monitored item subscription.
#
# 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 time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


def dataChangeNotification(sender, e):
    # Your code would do the processing here.
    pass


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 and hook events.
client = EasyUAClient()
client.DataChangeNotification += dataChangeNotification

print('Subscribing...')
handleArray = client.SubscribeMultipleMonitoredItems([
    EasyUAMonitoredItemArguments(
        None,
        UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer'),
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10845'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer'),
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer'),
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10855'),
        UAMonitoringParameters(1000)),
    ])

print('Getting monitored item arguments...')
monitoredItemArguments = client.GetMonitoredItemArguments(handleArray[2])
print('NodeDescriptor: ', monitoredItemArguments.NodeDescriptor, sep='')
print('SamplingInterval: ', monitoredItemArguments.MonitoringParameters.SamplingInterval, sep='')
print('PublishingInterval: ', monitoredItemArguments.SubscriptionParameters.PublishingInterval, sep='')

print('Waiting for 5 seconds...')
time.sleep(5)

print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()

print('Waiting for 5 seconds...')
time.sleep(5)

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

EasyUAClientCore Class
EasyUAClientCore Members
ChangeMultipleMonitoredItemSubscriptions Method
GetMonitoredItemArgumentsDictionary Method
SubscribeMultipleMonitoredItems Method

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