KeepAliveInterval Property (UAClientSessionParameters)

How frequently the server is pinged to see if communication is still working (in milliseconds).

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<UnitAttribute("ms")>
<ValueRangeAttribute(1, 2147483647)>
Public Property KeepAliveInterval As Integer

'Usage
 
Dim instance As UAClientSessionParameters
Dim value As Integer
 
instance.KeepAliveInterval = value
 
value = instance.KeepAliveInterval

[Unit("ms")]
[ValueRange(1, 2147483647)]
public int KeepAliveInterval {get; set;}

[Unit("ms")]
[ValueRange(1, 2147483647)]
public:
property int KeepAliveInterval {
   int get();
   void set (    int value);
}

Property Value

Frequency in milliseconds, or System.Threading.Timeout.Infinite to disable the keep alive monitoring.

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

Unit of measurement is ms.

The default value of this property is 5000.

Exceptions

Exception	Description
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. 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.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

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 interval controls (but does not directly mean) how much time elapses before a communication error is detected.

Note that by default, KeepAliveInterval value gets effectively clamped to 25% of the SessionTimeout.

This parameter is not interpreted by the component; it is simply passed down to the OPC UA Stack for processing.

Subscription Service Set: "When there are no Notifications to send within the keep-alive time interval, the Server sends a keep-alive Message … . If a Client fails to receive a Message after the keep-alive interval has expired, or if it determines that it has missed a Message, it can request the Server to resend one or more Messages."

In order to obtain or modify this parameter, in the default state (when OpcLabs.EasyOpc.UA.EasyUAClientCore.Isolated equals to false), access UAClientAdaptableParameters.SessionParameters property of static OpcLabs.EasyOpc.UA.EasyUAClientCore.AdaptableParameters. If you have set OpcLabs.EasyOpc.UA.EasyUAClientCore.Isolated to true, you need to access UAClientAdaptableParameters.SessionParameters property of OpcLabs.EasyOpc.UA.EasyUAClientCore.IsolatedParameters.

The getter method of this property is pure, i.e. it does not have observable side effects.

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

UAClientSessionParameters Class
UAClientSessionParameters Members
SessionTimeout Property

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