ReadItemValueArrayOfInt32(IEasyDAClient,String,String,String,Int32) Method

Reads a value of named OPC item, and converts it to an array of System.Int32. The value is requested from the OPC server using a corresponding data type.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadItemValueArrayOfInt32( _
   ByVal client As IEasyDAClient, _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal itemId As String, _
   ByVal valueAge As Integer _
) As Integer()

'Usage
 
Dim client As IEasyDAClient
Dim machineName As String
Dim serverClass As String
Dim itemId As String
Dim valueAge As Integer
Dim value() As Integer
 
value = IEasyDAClientExtension2.ReadItemValueArrayOfInt32(client, machineName, serverClass, itemId, valueAge)

[Extension()]
[NotNull()]
public static int[] ReadItemValueArrayOfInt32( 
   IEasyDAClient client,
   string machineName,
   string serverClass,
   string itemId,
   int valueAge
)

[Extension()]
[NotNull()]
public:
static array<int>^ ReadItemValueArrayOfInt32( 
   IEasyDAClient^ client,
   String^ machineName,
   String^ serverClass,
   String^ itemId,
   int valueAge
)

Parameters

client

The client object that will perform the operation.

This is typically the OpcLabs.EasyOpc.DataAccess.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

Contains OPC item identifier.

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

valueAge

Determines the age of value you would like to obtain (in milliseconds).

Return Value

Returns a value of the OPC item, converted to a type indicated by the method name.

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

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.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. 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.
OpcLabs.EasyOpc.OperationModel.OpcException	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.

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.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

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.

OpcLabs.EasyOpc.OperationModel.OpcException

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

The server(s) can be local or can be remotely accessed via DCOM.

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.

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

IEasyDAClientExtension2 Class
IEasyDAClientExtension2 Members
Overload List

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