ChangeItemSubscription Method (

Changes parameters of a subscription. Specify handle, and requested update rate.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Sub ChangeItemSubscription( _
   ByVal handle As Integer, _
   ByVal requestedUpdateRate As Integer _
)

'Usage
 
Dim instance As _EasyDAClient
Dim handle As Integer
Dim requestedUpdateRate As Integer
 
instance.ChangeItemSubscription(handle, requestedUpdateRate)

void ChangeItemSubscription( 
   int handle,
   int requestedUpdateRate
)

void ChangeItemSubscription( 
   int handle,
   int requestedUpdateRate
)

Parameters

handle: Item subscription handle as returned by the SubscribeItem method
requestedUpdateRate: The new requested update rate.

Remarks

It is more efficient to change multiple subscriptions using ChangeMultipleItemSubscriptions method.

Example

COM

VBScript

Rem This example shows how change the update rate of an existing subscription.

Option Explicit

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
WScript.ConnectObject Client, "Client_"

WScript.Echo "Subscribing..."
Dim handle: handle = Client.SubscribeItem("", "OPCLabs.KitServer.2", "Simulation.Random", 1000)

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.Echo "Changing subscription..."
Client.ChangeItemSubscription handle, 100

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.Echo "Unsubscribing..."
Client.UnsubscribeAllItems

WScript.Echo "Waiting for 10 seconds..."
WScript.Sleep 10*1000

WScript.DisconnectObject Client
Set Client = Nothing



Sub Client_ItemChanged(Sender, e)
    If Not (e.Succeeded) Then
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
        Exit Sub
    End If

    WScript.Echo e.Vtq
End Sub

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

_EasyDAClient Interface
_EasyDAClient Members

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