Topic Structure

The general structure of data logger MQTT topics is:

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

  • <baseTopic> : Configured in the data logger settings. Default: cs/v2

  • <msgType> : Indicates the type of message:

    • state - (Publish) Connection state message, including (online/offline) session info and (watchdog) indicators.

    • status - (Publish) System status table output.

    • metadata - (Publish) Deployment metadata and table schemas.

    • data - (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 - (Publish) Responses to command and control messages (sent on cc topic).

    • cc - (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 section.

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