> For the complete documentation index, see [llms.txt](https://support.powerio.com/hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.powerio.com/hub/powerio-r-system/en/h1.m300/feldbus-protokolle/application.md).

# Application

## Application Mode: How it works & benefits

The serial ports can be assigned to the installed [User-Applications](/hub/powerio-r-system/en/applications/available-apps.md) be assigned. 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.
* When the Application is running, the serial port cannot be changed.
* The serial port settings, such as baud rate, etc., are made in the selected 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** stopped.

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

2.) Under Serial Settings, 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. The assigned port is available in the Application under the same device path (e.g. `/dev/ttyPort2`).

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


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://support.powerio.com/hub/powerio-r-system/en/h1.m300/feldbus-protokolle/application.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.