BrowseServers Method (IEasyDAClient)

Browses the specified computer and returns information about OPC (Data Access) servers found.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<JetBrains.Annotations.ItemNotNullAttribute()>
<JetBrains.Annotations.MustUseReturnValueAttribute()>
<JetBrains.Annotations.NotNullAttribute()>
Function BrowseServers( _
   ByVal location As String, _
   ByVal technologies As OpcTechnologies _
) As ServerElementCollection

'Usage
 
Dim instance As IEasyDAClient
Dim location As String
Dim technologies As OpcTechnologies
Dim value As ServerElementCollection
 
value = instance.BrowseServers(location, technologies)

[JetBrains.Annotations.ItemNotNull()]
[JetBrains.Annotations.MustUseReturnValue()]
[JetBrains.Annotations.NotNull()]
ServerElementCollection BrowseServers( 
   string location,
   OpcTechnologies technologies
)

[JetBrains.Annotations.ItemNotNull()]
[JetBrains.Annotations.MustUseReturnValue()]
[JetBrains.Annotations.NotNull()]
ServerElementCollection^ BrowseServers( 
   String^ location,
   OpcTechnologies technologies
)

Parameters

location

Name of the machine. Determines the computer to browse for OPC servers. It may be an empty string, in which case the local computer will be browsed.

The value represents a UNC or DNS computer name. Any string can be passed to this parameter (i.e. will not cause System.ArgumentException), but not all values make sense and will work when an operation using them is attempted. IPv6 addresses are normally enclosed between '[' and ']'.

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

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.

This method never returns null (Nothing in Visual Basic).

The individual elements of the returned value are never null (Nothing in Visual Basic).

This return value of this method should not be ignored.

Exceptions

Exception Description

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.
System.ObjectDisposedException	An operation was performed on a disposed object.
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.

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.

System.ObjectDisposedException An operation was performed on a disposed object.

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.

Remarks

The server(s) can be local or can be remotely accessed via DCOM.

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

IEasyDAClient Interface
IEasyDAClient Members

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