OPC Studio User's Guide and Reference
ChangeDataChangeSubscription Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA Namespace > IEasyUAClientExtension Class : ChangeDataChangeSubscription Method
The client object that will perform the operation.

This is typically the EasyUAClient object.

The value of this parameter cannot be null (Nothing in Visual Basic).

Monitored item subscription handle as returned by the subscription method.
The sampling interval (in milliseconds) indicates the fastest rate at which the Server should sample its underlying source for data changes.

Valid values of this parameter are in the range from -1 to 2147483647 (Int32.MaxValue).

The value of absolute deadband.
Changes parameters of a data change subscription. Specify the handle, a new sampling interval and absolute deadband value.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Shared Sub ChangeDataChangeSubscription( _
   ByVal client As IEasyUAClient, _
   ByVal handle As Integer, _
   ByVal samplingInterval As Integer, _
   ByVal absoluteDeadbandValue As Double _
) 
'Usage
 
Dim client As IEasyUAClient
Dim handle As Integer
Dim samplingInterval As Integer
Dim absoluteDeadbandValue As Double
 
IEasyUAClientExtension.ChangeDataChangeSubscription(client, handle, samplingInterval, absoluteDeadbandValue)
[Extension()]
public static void ChangeDataChangeSubscription( 
   IEasyUAClient client,
   int handle,
   int samplingInterval,
   double absoluteDeadbandValue
)
[Extension()]
public:
static void ChangeDataChangeSubscription( 
   IEasyUAClient^ client,
   int handle,
   int samplingInterval,
   double absoluteDeadbandValue
) 

Parameters

client
The client object that will perform the operation.

This is typically the EasyUAClient object.

The value of this parameter cannot be null (Nothing in Visual Basic).

handle
Monitored item subscription handle as returned by the subscription method.
samplingInterval
The sampling interval (in milliseconds) indicates the fastest rate at which the Server should sample its underlying source for data changes.

Valid values of this parameter are in the range from -1 to 2147483647 (Int32.MaxValue).

absoluteDeadbandValue
The value of absolute deadband.
Exceptions
ExceptionDescription

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.

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

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

 

This method operates (at least in part) asynchronously, with respect to the caller. The actual execution of the operation may be delayed, and the outcome of the operation (if any) is provided to the calling code using an event notification, callback, or other means explained in the text. In a properly written program, this method 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 by the means the operation returns its outcome (if any), which is described in the text. For more information, see Do not catch any exceptions with asynchronous or multiple-operation methods.
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