MQTT Subscribe

Subscribe to an MQTT topic and receive message from the broker

Since R2023a

Add-On Required: This feature requires the Simulink Support Package for Android Devices add-on.

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Libraries:
Simulink Support Package for Android Devices / Communication

Description

Use the MQTT Subscribe block to receive messages from the message queuing telemetry transport (MQTT) broker on the specified topic.

Ports

Output

Data Length — Length of data

scalar (default)

The port outputs the actual length of the data received from the MQTT broker.

Data Types: int32

Data — Data received from MQTT broker

scalar

The block outputs the data received from the MQTT broker as an array of ASCII characters.

Data Types: uint8

Parameters

Topic — Topic for subscription

channels/<channelID>/subscribe (default) | any valid topic name

Specify a topic to which the client subscribes. A topic can have a maximum of 128 characters. For information on topics and their structure, see Topics in MQTT.

Maximum length of output message — Maximum length of data read from the MQTT broker

256 (default) | positive integer

Specify the maximum length of the data you want to receive at each sample time.

Sample time — Frequency to check for messages from MQTT broker

1 (default) | -1 | scalar

Specify how often the client checks for a new message from the broker. When you specify the sample time as -1, the block inherits its sample time based on the context of the block within the model.

Version History

Introduced in R2023a