FindFileSystem Method (IEasyUAFileTransfer)

Finds a file system object component under the specified OPC UA object.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<CanBeNullAttribute()>
Function FindFileSystem( _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal objectNodeDescriptor As UANodeDescriptor _
) As UANodeDescriptor

'Usage
 
Dim instance As IEasyUAFileTransfer
Dim endpointDescriptor As UAEndpointDescriptor
Dim objectNodeDescriptor As UANodeDescriptor
Dim value As UANodeDescriptor
 
value = instance.FindFileSystem(endpointDescriptor, objectNodeDescriptor)

[CanBeNull()]
UANodeDescriptor FindFileSystem( 
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor objectNodeDescriptor
)

[CanBeNull()]
UANodeDescriptor^ FindFileSystem( 
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ objectNodeDescriptor
)

Parameters

endpointDescriptor: Endpoint descriptor. Identifies the OPC-UA server.
objectNodeDescriptor: The node descriptor of the object that may aggregate the file system.

Return Value

If the node aggregates an OPC UA file system, the method returns a node descriptor of the file system, which is also its root directory. Otherwise, this method returns null.

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.
OpcLabs.EasyOpc.UA.OperationModel.UAException	The OPC UA 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.

OpcLabs.EasyOpc.UA.OperationModel.UAException

The OPC UA 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 OPC UA server may have a "file system" in it. There can be multiple file systems in the OPC UA server. each one rooted at a different node. In addition, the OPC UA server may have files that do not reside in any file system at all.

For description of the FileSystem Object in OPC UA specifications, see . "The Object representing the root of a file directory structure shall have the BrowseName FileSystem. An OPC UA Server may have different FileSystem Objects in the AddressSpace. HasComponent is used to reference a FileSystem from aggregating Objects like the Objects Folder or the Object representing a device."

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

IEasyUAFileTransfer Interface
IEasyUAFileTransfer Members
OpcLabs.EasyOpc.UA.FileTransfer.IEasyUAFileTransferExtension.FindFileSystem(OpcLabs.EasyOpc.UA.FileTransfer.IEasyUAFileTransfer,OpcLabs.EasyOpc.UA.UAEndpointDescriptor)

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