Browse for child branches. Specify machine name, and server class.
Syntax
Parameters
- client
- The client object that will perform the operation.
This is typically the EasyDAClient object.
The value of this parameter cannot be null
(Nothing
in Visual Basic).
- machineName
- Name of the machine (empty string for local computer).
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).
- serverClass
- Contains ProgID of the OPC server to browse.
The value of this parameter cannot be null
(Nothing
in Visual Basic).
- parentItemId
- ID of the parent branch to be browsed (empty string for root)
The value of this parameter cannot be null
(Nothing
in Visual Basic).
Return Value
The method returns a keyed collection of
OpcLabs.EasyOpc.DataAccess.AddressSpace.DANodeElement values, each containing information about a particular branch found. The keys of the keyed collection are the names of the branches.
This method never returns null
(Nothing
in Visual Basic).
The individual elements of the returned value are never null
(Nothing
in Visual Basic).
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. |
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