OPC Studio User's Guide and Reference
GetLowLowLimitPropertyValue(IEasyDAClient,ServerDescriptor,DANodeDescriptor) Method



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess.Extensions Namespace > IEasyDAClientExtension2 Class > GetLowLowLimitPropertyValue Method : GetLowLowLimitPropertyValue(IEasyDAClient,ServerDescriptor,DANodeDescriptor) Method
The client object that will perform the operation.
The OPC server involved in the operation.
The descriptor of the OPC node involved in the operation.
Obtains value of LoLo Limit OPC property for a given OPC item.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function GetLowLowLimitPropertyValue( _
   ByVal client As IEasyDAClient, _
   ByVal serverDescriptor As ServerDescriptor, _
   ByVal nodeDescriptor As DANodeDescriptor _
) As Double
'Usage
 
Dim client As IEasyDAClient
Dim serverDescriptor As ServerDescriptor
Dim nodeDescriptor As DANodeDescriptor
Dim value As Double
 
value = IEasyDAClientExtension2.GetLowLowLimitPropertyValue(client, serverDescriptor, nodeDescriptor)

Parameters

client
The client object that will perform the operation.
serverDescriptor
The OPC server involved in the operation.
nodeDescriptor
The descriptor of the OPC node involved in the operation.

Return Value

Returns a value of this OPC property for a specified OPC item, converted to a proper type.
Exceptions
ExceptionDescription

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.

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
Using implicit conversions, you can pass an item ID in place of node descriptor.
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