OPC Studio User's Guide and Reference
EasyDAClientHoldPeriods Class
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OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess.Engine Namespace : EasyDAClientHoldPeriods Class
Contains optimization parameters that reduce the load on the OPC server by keeping the connections open should they be soon needed again.
Object Model
EasyDAClientHoldPeriods ClassEasyDAClientHoldPeriods Class
Syntax
'Declaration
 
<CLSCompliantAttribute(True)>
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.DataAccess.Engine.ComTypes._EasyDAClientHoldPeriods)>
<ComVisibleAttribute(True)>
<GuidAttribute("D4F970F7-2E42-4883-996D-928390E5DA13")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<ValueControlAttribute("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.82.174.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=False, 
   Export=True, 
   PageId=10001)>
<SerializableAttribute()>
Public NotInheritable Class EasyDAClientHoldPeriods 
   Inherits OpcLabs.BaseLib.Parameters
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.BaseLib.ComTypes._Parameters, OpcLabs.EasyOpc.DataAccess.Engine.ComTypes._EasyDAClientHoldPeriods, System.ComponentModel.INotifyPropertyChanged, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
 
'Usage
 
Dim instance As EasyDAClientHoldPeriods
Example
// This example shows how the OPC server can quickly be disconnected after writing a value into one of its OPC items.
//
// 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.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClientHoldPeriods
{
    class TopicWrite
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();

            client.InstanceParameters.HoldPeriods.TopicWrite = 100; // in milliseconds

            try
            {
                client.WriteItemValue("", "OPCLabs.KitServer.2", "Simulation.Register_I4", 12345);
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
            }
        }
    }
}
Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.BaseLib.Parameters
            OpcLabs.EasyOpc.DataAccess.Engine.EasyDAClientHoldPeriods

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