# OpcClassicInterfaceCategory Enum

<span class="api-meta">since v2.8</span>

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

Specifies the category of an interface specification of OPC Classic.

## Syntax

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

```csharp
public enum OpcClassicInterfaceCategory
```

</div>

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

```vbnet
Public Enum OpcClassicInterfaceCategory
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [ValueType](https://learn.microsoft.com/dotnet/api/system.valuetype) → [Enum](https://learn.microsoft.com/dotnet/api/system.enum) → **OpcClassicInterfaceCategory**

## Fields

| Name | Value | Description |
|---|---|---|
| <a id="alarmevents"></a>`AlarmEvents` | `0` | OPC Alarms and Events. |
| <a id="dataaccess"></a>`DataAccess` | `2` | OPC Data Access. |
| <a id="historicaldataaccess"></a>`HistoricalDataAccess` | `4` | OPC Historical Data Access. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.8–v2.59 |