Topic Structure
===============
The general structure of data logger MQTT topics is:

.. code-block:: text

    <baseTopic>/<msgType>/<deviceId>/<msgName>

- **<baseTopic>** : Configured in the data logger settings. **Default**: ``cs/v2``

- **<msgType>** : Indicates the type of message:

  - `state <state.html>`_ - *(Publish)* Connection state message, including (online/offline) session info and (watchdog) indicators.  
  - `status <status.html>`_ - *(Publish)* System status table output.  
  - `metadata <metadata.html>`_ - *(Publish)* Deployment metadata and table schemas.
  - `data <data.rst>`_ - *(Publish)* Data published from DataTables defined in the CRBasic program.   
  - **pr** — *(Publish)* Payloads published from CRBasic program instructions such as ``MQTTPublishConstTable()``, ``MQTTPublishPublicTable()``, and ``MQTTPublishMeta()``.
  - `cr <commands.html>`_ - *(Publish)* Responses to command and control messages (sent on ``cc`` topic).  
  - `cc <commands.html>`_ - *(Subscribe)* Commands and control messages received by the data logger.

- **<deviceId>** : A unique identifier for the data logger.

  - ``<UID>`` (e.g., A1b2-C3d4-E5f6)  
  - ``<model>/<serialNumber>`` when a UID is not configured

  .. note::
    
    Most data loggers are assigned a unique identifier (UID) during the manufacturing process.
    If a data logger does not have a UID, you can assign or retrieve one using the **Device Configuration Utility**.
    For detailed steps on configuring a UID, see the `Onboard <onboard.rst>`_ section. 

- **<msgName>** : A flexible field that identifies the payload context — such as a data table name, command name, or other message-specific label.