# OpcServerBase Class

> Reference: Provides the base class of OpcServer and OpcDiscoveryServer, which maintains the base addresses and the life cycle (see State) of a server.

<span class="api-meta">abstract</span>

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.server">Opc.UaFx.Server</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">OpcServerBase Members</a></dd>
</dl>

Provides the base class of [OpcServer](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserver/) and [OpcDiscoveryServer](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcdiscoveryserver/), which maintains the base addresses and the life cycle (see [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state)) of a server.

## Syntax

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

```csharp
public abstract class OpcServerBase : OpcApplicationInstance<OpcTransport, OpcServerSecurity>
```

</div>

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

```vbnet
Public MustInherit Class OpcServerBase
    Inherits OpcApplicationInstance(Of OpcTransport, OpcServerSecurity)
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [OpcApplicationInstance](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcapplicationinstance-2/)&lt;[OpcTransport](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctransport/), [OpcServerSecurity](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserversecurity/)&gt; → **OpcServerBase**

## Implements

<ul class="api-implements">
<li><a href="https://learn.microsoft.com/dotnet/api/system.idisposable">IDisposable</a></li>
<li><a href="../opc.uafx.iopcapplicationinstance/">IOpcApplicationInstance</a></li>
<li><a href="../opc.uafx.iopcnamespaceresolver/">IOpcNamespaceResolver</a></li>
</ul>

## Derived types

- [OpcDiscoveryServer](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcdiscoveryserver/)
- [OpcServer](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserver/)

## Constructors

| Name | Description |
|---|---|
| [OpcServerBase](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#opcserverbase)<span class="api-meta">protected · 3 overloads</span> | Initializes a new instance of the OpcServerBase class using the `type` specified. |

## Properties

| Name | Description |
|---|---|
| [Address](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#address) | Gets or sets the (first) base address of the server. |
| [Addresses](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#addresses) | Gets a read-only collection of [Uri](https://learn.microsoft.com/dotnet/api/system.uri) instances representing the base addresses used by the server. |
| [AuthenticationLimits](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#authenticationlimits)<span class="api-meta">since v2.50</span> | Gets the [OpcAuthenticationLimits](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcauthenticationlimits/) instance used to maintain the different authentication limits used by the server. |
| [Binding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#binding) | Gets the [OpcServerBinding](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbinding/) instance used to maintain the different binding options used by the server application. |
| [Configuration](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#configuration)<span class="api-meta">override</span> | Gets or sets an instance of the [OpcApplicationConfiguration](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcapplicationconfiguration/) class which is used as a low-level representation of the code/file based server application configuration. |
| [Name](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#name) | Gets or sets the name of the server. |
| [Namespaces](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#namespaces)<span class="api-meta">override · since v2.12</span> | Gets a read-only collection of namespaces used by the server. |
| [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) | Gets a value that indicates the current state of the server. |

## Methods

| Name | Description |
|---|---|
| [CreateAuthenticationLimits](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#createauthenticationlimits)<span class="api-meta">protected · virtual · since v2.50</span> | Creates a new instance of the [OpcAuthenticationLimits](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcauthenticationlimits/) class. |
| [CreateConfiguration](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#createconfiguration)<span class="api-meta">protected · virtual</span> | Creates the configuration which is used to start the server. |
| [CreateSecurity](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#createsecurity)<span class="api-meta">protected · override · since v2.6</span> | Creates a new instance of the [OpcServerSecurity](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserversecurity/) class. |
| [CreateTransport](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#createtransport)<span class="api-meta">protected · override · since v2.6</span> | Creates a new instance of the [OpcTransport](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opctransport/) class. |
| [DenyIfNotStarted](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#denyifnotstarted)<span class="api-meta">protected</span> | Verifies whether the server is in started state. |
| [Dispose](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#dispose)<span class="api-meta">protected · override</span> | Releases the unmanaged resources used by the OpcServerBase and optionally releases the managed resources. |
| [GetInfo](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#getinfo) | Gets the information about the product of the server. |
| [GetInfoCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#getinfocore)<span class="api-meta">protected · virtual</span> | Provides the information about the product of the server. |
| [OnStarted](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onstarted)<span class="api-meta">protected · virtual</span> | Raises the [Started](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#started) event of the OpcServerBase. |
| [OnStarting](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onstarting)<span class="api-meta">protected · virtual</span> | Raises the [Starting](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#starting) event of the OpcServerBase. |
| [OnStateChanged](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onstatechanged)<span class="api-meta">protected · virtual</span> | Raises the [StateChanged](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#statechanged) event of the OpcServerBase. |
| [OnStopped](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onstopped)<span class="api-meta">protected · virtual</span> | Raises the [Stopped](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stopped) event of the OpcServerBase. |
| [OnStopping](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onstopping)<span class="api-meta">protected · virtual</span> | Raises the [Stopping](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stopping) event of the OpcServerBase. |
| [OnSuspended](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onsuspended)<span class="api-meta">protected · virtual · since v2.50</span> | Raises the [Suspended](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspended) event of the OpcServerBase. |
| [OnSuspending](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#onsuspending)<span class="api-meta">protected · virtual · since v2.50</span> | Raises the [Suspending](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspending) event of the OpcServerBase. |
| [RegisterAddress](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#registeraddress)<span class="api-meta">2 overloads</span> | Registers the `address` specified as one of the base addresses used by the server. |
| [Resume](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#resume)<span class="api-meta">since v2.11</span> | Resumes the suspended server. |
| [ResumeCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#resumecore)<span class="api-meta">protected · virtual · since v2.11</span> | When overridden in a derived class, resumes the suspended server. |
| [Setup](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#setup)<span class="api-meta">protected · override · since v2.6</span> | Sets up the `configuration` specified before the server is started. |
| [Start](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#start) | Starts the server. |
| [StartCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#startcore)<span class="api-meta">protected · virtual</span> | When overridden in a derived class, starts the server using the `configuration` specified. |
| [Stop](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stop) | Stops the server. |
| [StopCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stopcore)<span class="api-meta">protected · abstract</span> | When implemented in a derived class, stops the server. |
| [Suspend](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspend)<span class="api-meta">since v2.11</span> | Suspends the started server. |
| [SuspendCore](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspendcore)<span class="api-meta">protected · virtual · since v2.11</span> | When overridden in a derived class, suspends the started server. |
| [UnregisterAddress](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#unregisteraddress)<span class="api-meta">2 overloads</span> | Unregisters the `address` specified from the list of base addresses used by the server. |

## Events

| Name | Description |
|---|---|
| [Started](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#started) | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Started](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#started). |
| [Starting](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#starting) | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Starting](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#starting). |
| [StateChanged](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#statechanged) | Occurs when ever the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) property has been changed to a different value. |
| [Stopped](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stopped) | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Stopped](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#stopped). |
| [Stopping](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#stopping) | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Stopping](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#stopping). |
| [Suspended](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspended)<span class="api-meta">since v2.50</span> | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Suspended](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#suspended). |
| [Suspending](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#suspending)<span class="api-meta">since v2.50</span> | Occurs when the [State](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverbase/members#state) of the server changes to [Suspending](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcserverstate/#suspending). |

Inherits members from [OpcApplicationInstance&lt;OpcTransport, OpcServerSecurity&gt;](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.opcapplicationinstance-2/members).

## Applies to

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