# OpcDataChangeReceivedCallback Delegate

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.client">Opc.UaFx.Client</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
<dt>Also in</dt>
<dd>Opc.UaFx.Client</dd>
</dl>

Represents the method that will process monitored item data changes published from the server.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public delegate void OpcDataChangeReceivedCallback(
    IEnumerable<OpcDataChangeDataSetItem> dataChanges)
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Delegate Sub OpcDataChangeReceivedCallback(
    dataChanges As IEnumerable(Of OpcDataChangeDataSetItem))
```

</div>

## Parameters

| Name | Type | Description |
|---|---|---|
| `dataChanges` | [IEnumerable](https://learn.microsoft.com/dotnet/api/system.collections.generic.ienumerable-1)&lt;[OpcDataChangeDataSetItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangedatasetitem/)&gt; | A sequence of [OpcDataChangeDataSetItem](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatachangedatasetitem/) instances with new values of the monitored items the sequence belongs to. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.5–v2.59 |