QuickOPC User's Guide and Reference
WaitForMultiple(IEasyUAClient,IReadOnlyList<ValueTuple<UAMonitoredItemArguments,Func<UAAttributeDataResult,Boolean>>>) Method



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Extensions Namespace > IEasyUAClientExtension2 Class > WaitForMultiple Method : WaitForMultiple(IEasyUAClient,IReadOnlyList<ValueTuple<UAMonitoredItemArguments,Func<UAAttributeDataResult,Boolean>>>) Method
The client object that will perform the operation.
List of tuples, where each tuple consists of OPC-UA monitored item arguments, and a predicate on OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult determining when the wait is complete.
Subscribes to the specified nodes&attributes, and monitors their data until the predicates specified for each item become true, or the alloted time elapses.
Syntax

Parameters

client
The client object that will perform the operation.
argumentsAndExitPredicateList
List of tuples, where each tuple consists of OPC-UA monitored item arguments, and a predicate on OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult determining when the wait is complete.

Return Value

The function returns an array of OpcLabs.EasyOpc.UA.OperationModel.UAAttributeDataResult objects. The indices of elements in the output array are the same as those in the input list, argumentsAndExitPredicateList.
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.

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