QuickOPC User's Guide and Reference
ReadItemValueBoolean(IEasyDAClient,String,String,String) Method



OpcLabs.EasyOpcClassic Assembly > OpcLabs.EasyOpc.DataAccess.Extensions Namespace > IEasyDAClientExtension2 Class > ReadItemValueBoolean Method : ReadItemValueBoolean(IEasyDAClient,String,String,String) Method
The client object that will perform the operation.
Name of the machine. Determines the computer on which the OPC server is located. May be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.
Contains ProgID of the OPC server to read from.
Contains OPC item identifier.
Reads a value of named OPC item, and converts it to System.Boolean. The value is requested from the OPC server using a corresponding data type.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Overloads Shared Function ReadItemValueBoolean( _
   ByVal client As IEasyDAClient, _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal itemId As String _
) As Boolean
'Usage
 
Dim client As IEasyDAClient
Dim machineName As String
Dim serverClass As String
Dim itemId As String
Dim value As Boolean
 
value = IEasyDAClientExtension2.ReadItemValueBoolean(client, machineName, serverClass, itemId)
[Extension()]
public static bool ReadItemValueBoolean( 
   IEasyDAClient client,
   string machineName,
   string serverClass,
   string itemId
)
[Extension()]
public:
static bool ReadItemValueBoolean( 
   IEasyDAClient^ client,
   String^ machineName,
   String^ serverClass,
   String^ itemId
) 

Parameters

client
The client object that will perform the operation.
machineName
Name of the machine. Determines the computer on which the OPC server is located. May be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.
serverClass
Contains ProgID of the OPC server to read from.
itemId
Contains OPC item identifier.

Return Value

Returns a value of the OPC item, converted to a type indicated by the method name.
Exceptions
ExceptionDescription
The OPC "Classic" (or OPC XML-DA) operation has failed.
A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.
Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012, Windows Server 2016; .NET Core, .NET 5, .NET 6: Linux, macOS, Microsoft Windows

See Also

Reference

IEasyDAClientExtension2 Class
IEasyDAClientExtension2 Members
Overload List