MQTT Rx Queue

When AnyNet SMARTconnect™ is subscribed to a topic and receives new MQTT messages, it can perform either of the following functions:

• Immediately forward the messages on the AT port in URC format. See +EMQ Unsolicited Response Codes (URCs).

  The response format is:

  +EMQ:

  It includes the message index, length in bits, and forwarded MQTT message.
• If the MQTT Rx Queue is enabled, store up to three MQTT messages in a queue in the module’s volatile memory.

  If AnyNet SMARTconnect™ receives further messages, it overwrites the existing messages, starting with the oldest.

  Messages use the following +EMQREAD format:

  +EMQREAD:

  Use the [mqtt] mqttenablerxqueue parameter in the AnyNet SMARTconnect™ configuration file to enable or disable the MQTT Rx Queue.

Status flags

If the MQTT Rx Queue is enabled, you can use the following status flags to obtain information about the internal status of AnyNet SMARTconnect™:

• MQTT RX — Set when messages appear in the MQTT Rx Queue.
• MQTT RXov — Set when the oldest received message is overwritten.
• MQTT TX Internal error — Set when a message cannot be stored.
• MQTT TXov — Set when the oldest transmitted message is overwritten.
• MQTT TX OK — Set when a transmitted message is published.
• MQTT TX Refused — Set when the broker rejects a message or closes the SSL connection five times.
• Reboot required — Set when an update requires a reboot.
• Update fail — Set when a host firmware, configuration, or AnyNet SMARTconnect™ update fails.
• Update success — Set when a host firmware, configuration, or AnyNet SMARTconnect™ update completes.

The module clears the flags when their documented reset condition occurs.

Check the status flags with ETMINFO – displays AnyNet SMARTconnect™ and device information.