ReadMultipleValues(IEasyUAClient,UAEndpointDescriptor,UANodeDescriptor,UAAttributeId[]) Method

Reads values of multiple attributes. Reads values of multiple attributes of the same node, using array of attribute IDs as an input.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<ElementsNotNullAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadMultipleValues( _
   ByVal client As IEasyUAClient, _
   ByVal endpointDescriptor As UAEndpointDescriptor, _
   ByVal nodeDescriptor As UANodeDescriptor, _
   ByVal attributeIdArray() As UAAttributeId _
) As ValueResult()

'Usage
 
Dim client As IEasyUAClient
Dim endpointDescriptor As UAEndpointDescriptor
Dim nodeDescriptor As UANodeDescriptor
Dim attributeIdArray() As UAAttributeId
Dim value() As ValueResult
 
value = IEasyUAClientExtension.ReadMultipleValues(client, endpointDescriptor, nodeDescriptor, attributeIdArray)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public static ValueResult[] ReadMultipleValues( 
   IEasyUAClient client,
   UAEndpointDescriptor endpointDescriptor,
   UANodeDescriptor nodeDescriptor,
   UAAttributeId[] attributeIdArray
)

[Extension()]
[ElementsNotNull()]
[NotNull()]
public:
static array<ValueResult^>^ ReadMultipleValues( 
   IEasyUAClient^ client,
   UAEndpointDescriptor^ endpointDescriptor,
   UANodeDescriptor^ nodeDescriptor,
   array<UAAttributeId>^ attributeIdArray
)

Parameters

client: The client object that will perform the operation.
endpointDescriptor: Endpoint descriptor. Identifies the OPC-UA server.
nodeDescriptor: Node descriptor. Identifies the node in OPC server's address space.
attributeIdArray: Array of UAAttributeId. Array of attribute IDs specifying what to read from an OPC-UA server.

Return Value

Array of OpcLabs.BaseLib.OperationModel.ValueResult. Returns an array of value objects. Each object contains the actual value of an attribute. The indices of elements in the output array are the same as those in the input array, .

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.

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.

Remarks

The status codes of attributes should be 'good'; otherwise, a OpcLabs.BaseLib.OperationModel.ValueResult.Value of that attribute is not valid, and OpcLabs.BaseLib.OperationModel.OperationResult.Exception contains a non-null exception.

The size of the input array will become the size of the output array. The element positions (indices) in the output array are the same as in the input array.

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

Reference

IEasyUAClientExtension Class
IEasyUAClientExtension Members
Overload List

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