# OpcObjectNode Class

> Reference: Defines a logical unit to represent more complex information as a OpcVariableNode.

<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">OpcObjectNode Members</a></dd>
</dl>

Defines a logical unit to represent more complex information as a [OpcVariableNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcvariablenode/). Objects are used to represent systems, system components, real-world objects and software objects.

## Syntax

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

```csharp
public class OpcObjectNode : OpcInstanceNode
```

</div>

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

```vbnet
<OpcNodeType(58)>
Public Class OpcObjectNode
    Inherits OpcInstanceNode
```

</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/) → **OpcObjectNode**

## Implements

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

## Derived types

- [OpcAggregateConfigurationNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcaggregateconfigurationnode/)
- [OpcEventNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opceventnode/)
- [OpcFileNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcfilenode/)
- [OpcFolderNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcfoldernode/)
- [OpcHistoryConfigurationNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opchistoryconfigurationnode/)
- [OpcOrderedObjectListNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcorderedobjectlistnode/)
- [OpcOrderedObjectNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcorderedobjectnode/)
- [OpcStateMachineNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatemachinenode/)
- [OpcStateNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcstatenode/)
- [OpcTransitionNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctransitionnode/)

## Remarks

From a more abstract point of view objects are used to group variables and other objects in the address space. Therefore objects should be used when some common structures/groups of objects and/or variables should be described.

Simple objects only having one value (e.g. a simple heat sensor) can also be modelled as variables. However, extensibility mechanisms should be considered (e.g. a complex heat sensor subtype could have several values) and whether that object should be exposed as an object in the client's GUI or just as a value. Whenever a modeller is in doubt as to which solution to use the object having one variable should be preferred.

## Constructors

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

## Properties

| Name | Description |
|---|---|
| [DefaultReferenceTypeId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/members#defaultreferencetypeid)<span class="api-meta">protected · override</span> | Gets the default identifier which identifies the type that defines the underlying node reference within this [OpcInstanceNode](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcinstancenode/) is referenced by its parent node. |
| [DefaultTypeDefinitionId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/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. |
| [IsHistorizingEvents](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/members#ishistorizingevents)<span class="api-meta">since v2.54</span> | Gets or sets a value indiciating whether there exists an event history for the node. |

## Methods

| Name | Description |
|---|---|
| [AddNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/members#addnotifier)<span class="api-meta">override</span> | Adds the `node` to the collection of notifiers (= event sources) of this node. |
| [RemoveNotifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcobjectnode/members#removenotifier)<span class="api-meta">override</span> | Removes the `node` from the collection of notifiers (= event sources) of this node. |

Inherits members from [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 |