Contains information about which specifications the OPC server claims to support.

Object Model

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.ComTypes._ServerCategories)>
<ComVisibleAttribute(True)>
<GuidAttribute("19B240C8-9F3A-43EF-97ED-EBCFD8A0A583")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<CLSCompliantAttribute(True)>
<ValueControlAttribute("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.63.115.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=False, 
   Export=True, 
   PageId=10001)>
<SerializableAttribute()>
Public NotInheritable Class ServerCategories 
   Inherits OpcLabs.BaseLib.Info
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.ComTypes._ServerCategories, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

'Usage
 
Dim instance As ServerCategories

[ComDefaultInterface(OpcLabs.EasyOpc.ComTypes._ServerCategories)]
[ComVisible(true)]
[Guid("19B240C8-9F3A-43EF-97ED-EBCFD8A0A583")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[CLSCompliant(true)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.63.115.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public sealed class ServerCategories : OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.ComTypes._ServerCategories, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

[ComDefaultInterface(OpcLabs.EasyOpc.ComTypes._ServerCategories)]
[ComVisible(true)]
[Guid("19B240C8-9F3A-43EF-97ED-EBCFD8A0A583")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[CLSCompliant(true)]
[ValueControl("OpcLabs.BaseLib.Forms.Common.ObjectSerializationControl, OpcLabs.BaseLibForms, Version=5.63.115.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   DefaultReadWrite=false, 
   Export=true, 
   PageId=10001)]
[Serializable()]
public ref class ServerCategories sealed : public OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.ComTypes._ServerCategories, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable

Remarks

There are individual flags (properties) indicating the supported specifications.

If you want to retrieve a list of OPC Data Access servers registered on a local or remote computer, call the BrowseServers method, passing it the name or address of the remote machine (use empty string for local computer).

In QuickOPC.NET, you will receive back a ServerElementCollection object. If you want to connect to this OPC server later in your code by calling other methods, use the built-in conversion of ServerElement to a String or ServerDescriptor, and pass the resulting string as a serverClass or a serverUrl argument either directly to the method call, or to a constructor of ServerDescriptor object.

In QuickOPC-COM, if you want to connect to some OPC server later in your code by calling other methods, obtain the value of ServerElement.ServerClass property, and pass the resulting string as a serverClass argument to the method call that accepts it.

Each ServerElement contains information gathered about one OPC server found on the specified machine, including things like the server’s CLSID, ProgID, vendor name, and readable description. For an OPC XML server, it contains its URL.

Example 1

// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.

using System;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.DataAccess._EasyDAClient
{
    class BrowseServers
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyDAClient();
            ServerElementCollection serverElements;
            try
            {
                serverElements = client.BrowseServers("");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (ServerElement serverElement in serverElements)
                Console.WriteLine($"ServerElements(\"{serverElement.ClsidString}\").ProgId: {serverElement.ProgId}");
        }


        // Example output:
        //
        //ServerElements("c8a12f17-1e03-401e-b53d-6c654dd576da").ProgId: OPCLabs.KitServer.2
    }
}

// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.

var Client = new ActiveXObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient");
var ServerElements = Client.BrowseServers("")

for (var objEnum = new Enumerator(ServerElements) ; !objEnum.atEnd() ; objEnum.moveNext()) {
    var ServerElement = objEnum.item();
    WScript.Echo("ServerElements(\"" + ServerElement.UrlString + "\").ProgId: " + ServerElement.ProgId);
}

// This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.

$Client = new COM("OpcLabs.EasyOpc.DataAccess.EasyDAClient");

try
{
    $ServerElements = $Client->BrowseServers("");
}
catch (com_exception $e)
{
    printf("*** Failure: %s\n", $e->getMessage());
    Exit();
}

foreach ($ServerElements as $ServerElement)
{
    printf("ServerElements(\"s\").ProgIds\n", $ServerElement->ClsidString, $ServerElement->ProgId);
}

Rem This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.

Option Explicit

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
On Error Resume Next
Dim ServerElements: Set ServerElements = Client.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0

Dim ServerElement: For Each ServerElement In ServerElements
    WScript.Echo "ServerElements(""" & ServerElement.ClsidString & """).ProgId: " & ServerElement.ProgId
Next

Example 2

C#
VBScript

// This example shows all information available about categories that particular OPC servers do support.

using System;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples._ServerCategories
{
    class General
    {
        public static void Main1()
        {
            // Instantiate the OPC-DA client object.
            var daClient = new EasyDAClient();

            Console.WriteLine();
            Console.WriteLine("OPC DATA ACCESS");
            ServerElementCollection daServerElements;
            try
            {
                daServerElements = daClient.BrowseServers();
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }
            DumpServerElements(daServerElements);

            // Instantiate the OPC-A&E client object.
            var aeClient = new EasyAEClient();

            Console.WriteLine();
            Console.WriteLine("OPC ALARMS AND EVENTS");
            ServerElementCollection aeServerElements;
            try
            {
                aeServerElements = aeClient.BrowseServers();
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }
            DumpServerElements(aeServerElements);
        }

        private static void DumpServerElements(ServerElementCollection serverElements)
        {
            foreach (ServerElement serverElement in serverElements)
            {
                Console.WriteLine($"Categories of \"{serverElement.ProgId}\":");
                ServerCategories serverCategories = serverElement.ServerCategories;
                Console.WriteLine($"    .OpcAlarmsAndEvents10: {serverCategories.OpcAlarmsAndEvents10}");
                Console.WriteLine($"    .OpcDataAccess10: {serverCategories.OpcDataAccess10}");
                Console.WriteLine($"    .OpcDataAccess20: {serverCategories.OpcDataAccess20}");
                Console.WriteLine($"    .OpcDataAccess30: {serverCategories.OpcDataAccess30}");
                Console.WriteLine($"    .ToString(): {serverCategories}");
            }
        }

        
        // Example output:
        //
        //OPC DATA ACCESS
        //Categories of "OPCLabs.KitServer.2":
        //    .OpcAlarmsAndEvents10: False
        //    .OpcDataAccess10: True
        //    .OpcDataAccess20: True
        //    .OpcDataAccess30: True
        //    .ToString(): (OpcDataAccess10, OpcDataAccess20, OpcDataAccess30)
        //
        //OPC ALARMS AND EVENTS
        //Categories of "OPCLabs.KitEventServer.2":
        //    .OpcAlarmsAndEvents10: True
        //    .OpcDataAccess10: False
        //    .OpcDataAccess20: False
        //    .OpcDataAccess30: False
        //    .ToString(): (OpcAlarmsAndEvents10)
    }
}

Rem This example shows all information available about categories that particular OPC servers do support.

Option Explicit

Sub DumpServerElements(ByVal ServerElements)
Dim ServerElement: For Each ServerElement In ServerElements
    WScript.Echo "Categories of """ & ServerElement.ProgID & """:"
    With ServerElement.ServerCategories
        WScript.Echo Space(4) & ".OpcAlarmsAndEvents10: " & .OpcAlarmsAndEvents10
        WScript.Echo Space(4) & ".OpcDataAccess10: " & .OpcDataAccess10
        WScript.Echo Space(4) & ".OpcDataAccess20: " & .OpcDataAccess20
        WScript.Echo Space(4) & ".OpcDataAccess30: " & .OpcDataAccess30
        WScript.Echo Space(4) & ".ToString(): " & .ToString()
    End With
Next
End Sub



Dim DAClient: Set DAClient = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
WScript.Echo
WScript.Echo "OPC DATA ACCESS"
On Error Resume Next
Dim DAServerElements: Set DAServerElements = DAClient.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0
DumpServerElements DAServerElements

Dim AEClient: Set AEClient = CreateObject("OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient")
WScript.Echo
WScript.Echo "OPC ALARMS AND EVENTS"
On Error Resume Next
Dim AEServerElements: Set AEServerElements = AEClient.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0
DumpServerElements AEServerElements

Example 3

C#
VBScript

// This example shows all information available about OPC servers.

using System;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

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

            ServerElementCollection serverElements;
            try
            {
                serverElements = client.BrowseServers();
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (ServerElement serverElement in serverElements)
            {
                Console.WriteLine($"Information about server \"{serverElement}\":");
                Console.WriteLine($"    .ServerClass: {serverElement.ServerClass}");
                Console.WriteLine($"    .ClsidString: {serverElement.ClsidString}");
                Console.WriteLine($"    .ProgId: {serverElement.ProgId}");
                Console.WriteLine($"    .Description: {serverElement.Description}");
                Console.WriteLine($"    .Vendor: {serverElement.Vendor}");
                Console.WriteLine($"    .ServerCategories: {serverElement.ServerCategories}");
                Console.WriteLine($"    .VersionIndependentProgId: {serverElement.VersionIndependentProgId}");
            }


            // Example output:
            //
            //Information about server "opcda:OPCLabs.KitServer.2%7Bc8a12f17-1e03-401e-b53d-6c654dd576da%7D":
            //    .ServerClass: OPCLabs.KitServer.2
            //    .ClsidString: c8a12f17-1e03-401e-b53d-6c654dd576da
            //    .ProgId: OPCLabs.KitServer.2
            //    .Description: OPC Labs Kit Server
            //    .Vendor: OPC Labs, http://www.opclabs.com
            //    .ServerCategories: (OpcDataAccess10, OpcDataAccess20, OpcDataAccess30)
            //    .VersionIndependentProgId: OPCLabs.KitServer
        }
    }
}

Rem This example shows all information available about OPC servers.

Option Explicit

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
On Error Resume Next
Dim ServerElements: Set ServerElements = Client.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0

Dim ServerElement: For Each ServerElement In ServerElements
    WScript.Echo "Information about server """ & ServerElement & """:"
    With ServerElement
        WScript.Echo Space(4) & ".ServerClass: " & .ServerClass
        WScript.Echo Space(4) & ".ClsidString: " & .ClsidString
        WScript.Echo Space(4) & ".ProgId: " & .ProgId
        WScript.Echo Space(4) & ".Description: " & .Description
        WScript.Echo Space(4) & ".Vendor: " & .Vendor
        WScript.Echo Space(4) & ".ServerCategories.ToString(): " & .ServerCategories.ToString()
        WScript.Echo Space(4) & ".VersionIndependentProgId: " & .VersionIndependentProgId
    End With
Next

Example

VBScript
CSharp

Rem This example shows all information available about categories that particular OPC servers do support.

Option Explicit

Sub DumpServerElements(ByVal ServerElements)
Dim ServerElement: For Each ServerElement In ServerElements
    WScript.Echo "Categories of """ & ServerElement.ProgID & """:"
    With ServerElement.ServerCategories
        WScript.Echo Space(4) & ".OpcAlarmsAndEvents10: " & .OpcAlarmsAndEvents10
        WScript.Echo Space(4) & ".OpcDataAccess10: " & .OpcDataAccess10
        WScript.Echo Space(4) & ".OpcDataAccess20: " & .OpcDataAccess20
        WScript.Echo Space(4) & ".OpcDataAccess30: " & .OpcDataAccess30
        WScript.Echo Space(4) & ".ToString(): " & .ToString()
    End With
Next
End Sub



Dim DAClient: Set DAClient = CreateObject("OpcLabs.EasyOpc.DataAccess.EasyDAClient")
WScript.Echo
WScript.Echo "OPC DATA ACCESS"
On Error Resume Next
Dim DAServerElements: Set DAServerElements = DAClient.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0
DumpServerElements DAServerElements

Dim AEClient: Set AEClient = CreateObject("OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient")
WScript.Echo
WScript.Echo "OPC ALARMS AND EVENTS"
On Error Resume Next
Dim AEServerElements: Set AEServerElements = AEClient.BrowseServers("")
If Err.Number <> 0 Then
    WScript.Echo "*** Failure: " & Err.Source & ": " & Err.Description
    WScript.Quit
End If
On Error Goto 0
DumpServerElements AEServerElements

// This example shows all information available about categories that particular OPC servers do support.

using System;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples._ServerCategories
{
    class General
    {
        public static void Main1()
        {
            // Instantiate the OPC-DA client object.
            var daClient = new EasyDAClient();

            Console.WriteLine();
            Console.WriteLine("OPC DATA ACCESS");
            ServerElementCollection daServerElements;
            try
            {
                daServerElements = daClient.BrowseServers();
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }
            DumpServerElements(daServerElements);

            // Instantiate the OPC-A&E client object.
            var aeClient = new EasyAEClient();

            Console.WriteLine();
            Console.WriteLine("OPC ALARMS AND EVENTS");
            ServerElementCollection aeServerElements;
            try
            {
                aeServerElements = aeClient.BrowseServers();
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }
            DumpServerElements(aeServerElements);
        }

        private static void DumpServerElements(ServerElementCollection serverElements)
        {
            foreach (ServerElement serverElement in serverElements)
            {
                Console.WriteLine($"Categories of \"{serverElement.ProgId}\":");
                ServerCategories serverCategories = serverElement.ServerCategories;
                Console.WriteLine($"    .OpcAlarmsAndEvents10: {serverCategories.OpcAlarmsAndEvents10}");
                Console.WriteLine($"    .OpcDataAccess10: {serverCategories.OpcDataAccess10}");
                Console.WriteLine($"    .OpcDataAccess20: {serverCategories.OpcDataAccess20}");
                Console.WriteLine($"    .OpcDataAccess30: {serverCategories.OpcDataAccess30}");
                Console.WriteLine($"    .ToString(): {serverCategories}");
            }
        }

        
        // Example output:
        //
        //OPC DATA ACCESS
        //Categories of "OPCLabs.KitServer.2":
        //    .OpcAlarmsAndEvents10: False
        //    .OpcDataAccess10: True
        //    .OpcDataAccess20: True
        //    .OpcDataAccess30: True
        //    .ToString(): (OpcDataAccess10, OpcDataAccess20, OpcDataAccess30)
        //
        //OPC ALARMS AND EVENTS
        //Categories of "OPCLabs.KitEventServer.2":
        //    .OpcAlarmsAndEvents10: True
        //    .OpcDataAccess10: False
        //    .OpcDataAccess20: False
        //    .OpcDataAccess30: False
        //    .ToString(): (OpcAlarmsAndEvents10)
    }
}

Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.EasyOpc.ServerCategories

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012, Windows Server 2016; .NET Core, .NET 5, .NET 6: Linux, macOS, Microsoft Windows

Reference

ServerCategories Members
OpcLabs.EasyOpc Namespace