# OpcDataItemNode Class

> Reference: Defines a specialisation of the OpcDataVariableNode which defines the general characteristics of a data item.

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx">Opc.UaFx</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
<dt>Members</dt>
<dd><a href="./members">OpcDataItemNode Members</a></dd>
</dl>

Defines a specialisation of the [OpcDataVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatavariablenode/) which defines the general characteristics of a data item.

## Syntax

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

```csharp
public class OpcDataItemNode : OpcDataVariableNode
```

</div>

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

```vbnet
<OpcNodeType(2365)>
Public Class OpcDataItemNode
    Inherits OpcDataVariableNode
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/) → [OpcInstanceNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcinstancenode/) → [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/) → [OpcDataVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdatavariablenode/) → **OpcDataItemNode**

## Implements

<ul class="api-implements">
<li><a href="../opc.uafx.iopcnode/">IOpcNode</a></li>
<li><a href="../opc.uafx.iopcnodeinfo/">IOpcNodeInfo</a></li>
<li><a href="../opc.uafx.iopcvariablenodeinfo/">IOpcVariableNodeInfo</a></li>
</ul>

## Derived types

- [OpcAnalogItemNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcanalogitemnode/)
- [OpcAnalogUnitNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcanalogunitnode/)
- [OpcDataItemNode&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode-1/)
- [OpcDiscreteItemNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdiscreteitemnode/)

## Constructors

| Name | Description |
|---|---|
| [OpcDataItemNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#opcdataitemnode)<span class="api-meta">18 overloads</span> | Initializes a new instance of the OpcDataItemNode class accessible by the `name` specified. |

## Properties

| Name | Description |
|---|---|
| [DefaultTypeDefinitionId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#defaulttypedefinitionid)<span class="api-meta">protected · override</span> | Gets the default identifier which identifies the node that defines the underlying node type from that this [OpcInstanceNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcinstancenode/) has been created. |
| [Definition](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#definition) | Gets or sets a vendor-specific, human readable string that specifies how the value of this data item is calculated. |
| [DefinitionNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#definitionnode) | Gets the [OpcPropertyNode&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcpropertynode-1/) of the [Definition](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#definition) property. |
| [ValuePrecision](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#valueprecision) | Gets or sets a value which specifies the maximum precision that the server can maintain for the item based on restrictions in the target environment. |
| [ValuePrecisionNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#valueprecisionnode) | Gets the [OpcPropertyNode&lt;T&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcpropertynode-1/) of the [ValuePrecision](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#valueprecision) property. |

## Methods

| Name | Description |
|---|---|
| [InitializeDefaults](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcdataitemnode/members#initializedefaults)<span class="api-meta">protected · override</span> | Initializes the default values used by the OpcDataItemNode. |

Inherits members from [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/members), [OpcInstanceNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcinstancenode/members), [OpcNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcnode/members).

## Applies to

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