# Application

## Application Mode: How it works & benefits

{% hint style="info" %}
**Note:**\
To be able to use the serial ports in Applications, **at least firmware version v4.0** or higher must be used.
{% endhint %}

The serial ports can be assigned to the installed [User Applications](https://github.com/powerIO-GmbH/support-hub/blob/main/space-powerio-system/de/t1.b100/feldbus-protokolle/broken-reference/README.md) For example, the User Application [CODESYS](/hub/powerio-r-system/en/applications/available-apps/codesys.md) or the [HVAC Cloud Adapter](/hub/powerio-r-system/en/applications/available-apps/hvac-cloud-adapter.md) can use the serial ports.

### Selection for Application Mode

* The serial port can be assigned to an Application when the Application is stopped.
* If the Application is running, the serial port cannot be changed.
* The settings of the serial port, such as baud rate etc., are made in the chosen Application.

<figure><img src="/files/bc3f6f65e116091f503860371be233fae1c3e615" alt=""><figcaption><p>Selection of the serial port for an installed Application</p></figcaption></figure>

### Example Application Mode

1.) If the Application is not stopped, it must be stopped under **Applications** -> **Installed powerIO packages** be stopped.

<figure><img src="/files/c6a014ce7e6904302f97baa259e3e77b88e52c97" alt=""><figcaption><p>Stopping the Application</p></figcaption></figure>

2.) Under Serial Settings (or Extended Port), assign the respective port to the Application.

<figure><img src="/files/677c003dc23fcb9de4026abaebdc37d5b0576b5a" alt=""><figcaption><p>Assign serial port to the Application</p></figcaption></figure>

3.) Restart the Application **Applications** -> **Installed powerIO packages**

<figure><img src="/files/0990b4c5f41867f9cf784d00e206b1051efe8b70" alt=""><figcaption><p>Start Application</p></figcaption></figure>

4.) Use the port in the Application

<figure><img src="/files/d8ffcff14595bdb79e9f600f1ea34be7839908e8" alt=""><figcaption><p>Serial Port 2 in Application HVAC Cloud Adapter</p></figcaption></figure>


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