The MQTT Publisher application operates on the Kaspersky IoT Secure Gateway 1000 software platform. The application is responsible for transmitting data collected by the OPC UA Client application to an MQTT broker located in an external network. Data transmission security is ensured by TLS encryption.
The MQTT Publisher application only functions in tandem with the OPC UA Client application. For the application to function correctly, the user must configure the MQTT broker that will receive data from the application.
The MQTT Publisher application supports only version 3.1.1 of the MQTT protocol. The MQTT Publisher application has the following functional characteristics:
- Only one MQTT client can connect to one MQTT broker.
- MQTT Publisher uses the value «1» for the Clean Session flag with each connection to the MQTT broker.
- The qualityOfService parameter value is shared among all messages published by MQTT Publisher to topics (parameter topics), including service topics (heartbeat, lastWill, keepAlive).
- The qualityOfService parameter value cannot be configured separately for each message published by MQTT Publisher to topics (parameter topics).
- MQTT Publisher does not use the retain flag when sending messages, including for the LWT message (which notifies of the client’s incorrect disconnection).
- Setting the keepAlive parameter value to 0 does not disable the «keep alive» mechanism (a mechanism to disconnect the client due to inactivity).
- MQTT Publisher ignores the lack of response from the MQTT broker for an extended period and does not close the connection.
- In case of a connection break, no more than 10 published messages may be lost after the connection is restored and if there is free space in the buffer.
- The MQTT Publisher application may stop transmitting data to the MQTT broker after stopping and restarting. To restore the application’s proper functionality, you will need to reboot the Kaspersky IoT Secure Gateway 1000.
- If you configure the MQTT Publisher application to start manually and the OPC UA Client application to start automatically, both applications will be in a stopped state when the Kaspersky IoT Secure Gateway 1000 is powered on. The reverse configuration (manual start for the OPC UA Client application, automatic start for MQTT Publisher) works correctly.
For detailed instructions on the use and configuration of the application, refer to the user manual available on the Aprotech company website.
Use of the application is possible only after signing a Software License Agreement with the Rights Holder (Aprotech LLC).
