Browses the specified computer and returns information about OPC (Alarms and Events) servers found.
Syntax
Parameters
- location
- Name of the machine. Determines the computer to browse for OPC servers. May be an empty string, in which case the local computer will be browsed.
- technologies
- The OPC technologies to be used for server browsing.
Return Value
The method returns a keyed collection of
OpcLabs.EasyOpc.ServerElement values, each containing information about a particular OPC server found on the specified machine. The keys of the keyed collection are the server's CLSIDs.
Exceptions
| Exception | Description |
|---|
| System.ArgumentNullException |
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. |
| OpcLabs.EasyOpc.OperationModel.OpcException |
The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow
common handling of various kinds of errors. The System.Exception.InnerException always contains
information about the actual error cause.
This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately. |
Example
.NET
// This example shows how to obtain all ProgIDs of all OPC Alarms and Events servers on the local machine.
using System;
using System.Diagnostics;
using OpcLabs.EasyOpc;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.OperationModel;
namespace DocExamples.AlarmsAndEvents._EasyAEClient
{
class BrowseServers
{
public static void Main1()
{
// Instantiate the client object.
var client = new EasyAEClient();
ServerElementCollection serverElements;
try
{
serverElements = client.BrowseServers("");
}
catch (OpcException opcException)
{
Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
return;
}
foreach (ServerElement serverElement in serverElements)
{
Debug.Assert(serverElement != null);
Console.WriteLine("serverElements[\"{0}\"].ProgId: {1}", serverElement.Clsid, serverElement.ProgId);
}
}
}
}
# This example shows how to obtain all ProgIDs of all OPC Data Access servers on the local machine.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
# Import .NET namespaces.
from OpcLabs.EasyOpc.DataAccess import *
from OpcLabs.EasyOpc.OperationModel import *
# Instantiate the client object
client = EasyDAClient()
# Perform the operation
try:
serverElements = IEasyDAClientExtension.BrowseServers(client, '')
except OpcException as opcException:
print('*** Failure: ' + opcException.GetBaseException().Message)
exit()
# Display results
for serverElement in serverElements:
print('ServerElements("' + serverElement.ClsidString + '"): ' + serverElement.ProgId)
' This example shows how to obtain all ProgIDs of all OPC Alarms and Events servers on the local machine.
Imports OpcLabs.EasyOpc
Imports OpcLabs.EasyOpc.AlarmsAndEvents
Imports OpcLabs.EasyOpc.OperationModel
Namespace AlarmsAndEvents._EasyAEClient
Friend Class BrowseServers
Public Shared Sub Main1()
Dim client = New EasyAEClient()
Dim serverElements As ServerElementCollection
Try
serverElements = client.BrowseServers("")
Catch opcException As OpcException
Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
Exit Sub
End Try
For Each serverElement As ServerElement In serverElements
Debug.Assert(serverElement IsNot Nothing)
Console.WriteLine("serverElements[""{0}""].ProgId: {1}", serverElement.Clsid, serverElement.ProgId)
Next serverElement
End Sub
End Class
End Namespace
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
