MQTT AT commands

The MQTT client registers each topic with an index that is used to publish the messages. The response indicates acceptance or rejection of the topic. Optionally, you can configure a single fixed topic so the Cinterion® ELS61 Wireless Module need not keep track of topic indices for sending or receiving data.

The MQTT client supports QoS 0 and 1, and always connects to the broker as a clean session. All publish messages are queued in a non-volatile flash memory until they are sent to the broker. For QoS 1 messages, AnyNet SMARTconnect™ waits for a puback from the broker before discarding the sent data and transmitting the next message. This mechanism queues messages while a network connection is not available, and forwards messages when the connection establishes.