Short summary

Name	`MQTT_Subscribe`
→POU type	→function
Category	more system blocks, MQTT
Graphical interface
Available since	version 1.28.0 (for logi.CAD 3) and version 2.3.1301 of the →runtime system – initial variant version 1.108.0 (for logi.CAD 3) and version 3.18.0 of the →runtime system – enhancement: data type `STRING` for existing input `topic` (instead of `STRING[255]`); data type `MQTT_RC` for output `rc` (instead of `DINT`) This block is supported for →Raspberry Pi.

Functionality

The block subscribes to a topic for an established connection determined by a connection handle.

The data is transferred by means of an already existing MQTT broker

	Identifier	→Data type	Description
Inputs:	`ch`	`DINT`	connection handler (as obtained by the MQTT_Connect block)
Inputs:	`topic`	`STRING`	topic to subscribe to
Outputs:	`rc`	`MQTT_RC`	return code of involved MQTT functions as specified in data type `MQTT_RC`

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.