# Configure a subscription

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**Prerequisite** \
You have created a new subscription, as explained in [↗ Broker details -> Create new subscription](https://docs.buildings.ability.abb/collection/english-v14/connectivity-as-a-service/connect-devices-with-abb-buildingpro/configure-client#neue-subscription-erstellen) above.
{% endhint %}

## Overview

<div data-full-width="true"><figure><img src="https://content.gitbook.com/content/Nyvwhz1kEMXcHf4HLuZ8/blobs/9TfB6vpqxjkjEolYGMII/DocsConnection%20Neue_Subscription.png" alt=""><figcaption><p>Fig. 1 – Creating a new subscription</p></figcaption></figure></div>

<table><thead><tr><th width="84.33333333333331">Icon</th><th>Description</th><th>Details</th></tr></thead><tbody><tr><td><strong>[A]</strong></td><td>Topic preview</td><td>In this section you see a preview of the incoming data</td></tr><tr><td><strong>[A1]</strong></td><td>Entering the topic preview</td><td>Enter an MQTT topic here. Its data will appear in the preview. <br><br>Important: In this field, you enter <strong>NOT</strong> the topic for which you want to create a subscription – this is done in <strong>[C]</strong></td></tr><tr><td><strong>[B]</strong></td><td>Name</td><td>Give the subscription a name. The subscription will be displayed under this name in the subscription list (in the broker details)</td></tr><tr><td><strong>[C]</strong></td><td>Topic</td><td>Enter the MQTT topic here for which you want to create a subscription.</td></tr><tr><td><strong>[D]</strong></td><td>QoS (Quality of Service)</td><td>Select a value. QoS indicates the level of message delivery between the MQTT broker and the connected clients</td></tr><tr><td><strong>[E]</strong></td><td>One or more formats</td><td>Choose whether a single format or multiple formats should be applied to the data. -<a href="#ein-oder-mehrere-formate">> One or more formats</a></td></tr><tr><td><strong>[F]</strong></td><td>Create format</td><td>If you want to define a new format, click here. The window opens <a href="../configure-a-format">↗ Format </a>configure</td></tr><tr><td><strong>[G]</strong></td><td>Select existing format</td><td>As an alternative to <strong>[F]</strong> you can also select an existing format</td></tr><tr><td><strong>[H]</strong></td><td>Save</td><td>Click to save the subscription</td></tr></tbody></table>

## One or more formats

<figure><img src="https://content.gitbook.com/content/Nyvwhz1kEMXcHf4HLuZ8/blobs/MiDgK2HgVBqkkp5ffRzj/image.png" alt=""><figcaption></figcaption></figure>

Choose whether a single format or multiple formats should be applied to the incoming data.

◈ If you select *Single* the same format will be used for all incoming data.

◈ If you select *Multiple* select, you can differentiate the data processing – depending on *Topic*. This means: Within a subscription, different topics can be processed with different formats. For this, use **Pattern**to define which data belongs to which format.

**Example:**

You subscribe to the topic `levels/+`.\
There are two actual topics:

* `levels/level1` → this data should be processed with **Decoder A** be processed
* `levels/level2` → this data should be processed with **Decoder B** be processed

Then in Multiple mode, enter two pairs:

| Pattern         | format    |
| --------------- | --------- |
| `levels/level1` | Decoder A |
| `levels/level2` | Decoder B |

▷ This way, the data is automatically decoded with the appropriate format depending on the topic.<br>


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