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Stored procedures
ConstantDescriptionUsed by the functions
mqttQualityAtLeastOnceThe message will be delivered at least once. The client will transmit the message several times if necessary until the server (broker) confirms that the message was transmitted on the network.MQTTSubscribe, MQTTPublish
mqttQualityAtMostOnceThe message will be delivered once at most. The message is not stored. It is sent without guarantee of receipt. The MQTT (broker) does not inform the sender that the message was received. The message can be lost if the client is disconnected or if the server is stopped.MQTTSubscribe, MQTTPublish
mqttQualityExactlyOnceThe message will be necessarily saved by the issuer. It will be transmitted as long as the receiver does not confirm its sending on the network. The issuer is using a sophisticated recognition with the server (broker) to avoid duplicating messages. This mode is slower but it is more secure.MQTTSubscribe, MQTTPublish
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  • Version 22
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Last update: 05/26/2022

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