OPC Studio User's Guide and Reference
GetMultiplePropertyValues(IEasyDAClient,String,String,String,DAPropertyId[]) Method



OpcLabs.EasyOpcClassicCore Assembly > OpcLabs.EasyOpc.DataAccess Namespace > IEasyDAClientExtension Class > GetMultiplePropertyValues Method : GetMultiplePropertyValues(IEasyDAClient,String,String,String,DAPropertyId[]) Method
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).

Name of the machine. Determines the computer on which the OPC server is located. It 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.

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).

Contains ProgID of the OPC server to read from.

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

The Item ID of the OPC item involved in the operation.

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

Array of Property IDs being obtained

Because the DAPropertyId has an implicit conversion from System.Int64 and DAPropertyIds, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a long integer (representing the numerical value of the access rights), or an element of the DAPropertyIds enumeration in place of this parameter, and the corresponding Property Id specification will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the DAPropertyId Constructor(Int64) or DAPropertyId Constructor(DAPropertyIds) constructor instead.

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

Gets values of multiple OPC properties, using individual parameters specifying the OPC server, and OPC Item ID.
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function GetMultiplePropertyValues( _
   ByVal client As IEasyDAClient, _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal itemId As String, _
   ByVal propertyIdArray() As DAPropertyId _
) As ValueResult()
'Usage
 
Dim client As IEasyDAClient
Dim machineName As String
Dim serverClass As String
Dim itemId As String
Dim propertyIdArray() As DAPropertyId
Dim value() As ValueResult
 
value = IEasyDAClientExtension.GetMultiplePropertyValues(client, machineName, serverClass, itemId, propertyIdArray)
[Extension()]
[NotNull()]
public static ValueResult[] GetMultiplePropertyValues( 
   IEasyDAClient client,
   string machineName,
   string serverClass,
   string itemId,
   DAPropertyId[] propertyIdArray
)

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. Determines the computer on which the OPC server is located. It 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.

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 read from.

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

itemId
The Item ID of the OPC item involved in the operation.

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

propertyIdArray
Array of Property IDs being obtained

Because the DAPropertyId has an implicit conversion from System.Int64 and DAPropertyIds, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a long integer (representing the numerical value of the access rights), or an element of the DAPropertyIds enumeration in place of this parameter, and the corresponding Property Id specification will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the DAPropertyId Constructor(Int64) or DAPropertyId Constructor(DAPropertyIds) constructor instead.

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

The individual elements of the parameter value cannot be null (Nothing in Visual Basic).

Return Value

The function returns an array of OpcLabs.BaseLib.OperationModel.ValueResult objects. The indices of elements in the output array are the same as those in the input array.

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

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

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.

Remarks

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

 

This is a multiple-operation method. In a properly written program, it does not throw any exceptions. You should therefore not put try/catch statements or similar constructs around calls to this method. The only exceptions thrown by this method are for usage errors, i.e. when your code violates the usage contract of the method, such as passing in invalid arguments or calling the method when the state of the object does not allow it. Any operation-related errors (i.e. errors that depend on external conditions that your code cannot reliably check) are indicated in the result objects returned by the method. For more information, see Multiple-operation Methods and Do not catch any exceptions with asynchronous or multiple-operation methods.
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