MQTT_Connect block

Short summary

Name	`MQTT_Connect`
→POU type	→function
Category	more system blocks, MQTT
Graphical interface
Available since	version 1.28.0 (for Neuron Power Engineer) and version 2.3.1301 of the →runtime system – initial variant version 1.108.0 (for Neuron Power Engineer) and version 3.18.0 of the →runtime system – enhancement: data type `STRING` for existing inputs `address`, `clientId` (instead of `STRING[255]`); new inputs `username`, `password`, `useSSL`; data type `MQTT_RC` for output `rc` (instead of `DINT`) This block is supported for →Raspberry Pi.

Functionality

The block connects a controller to the →MQTT broker the address of which is specified at input address. An arbitrary client ID can be supplied to the connection.

The data is transferred by means of an already existing MQTT broker (see "Preparing/Realizing data transfer via MQTT").

Inputs, outputs, return value

	Identifier	→Data type	Description
Inputs:	`address`	`STRING`	address of the MQTT broker (`tcp://<ip>:<port>`)
	`clientId`	`STRING`	client ID of this connection Each connection needs to have an identifier that is unique for all connections to the MQTT broker.
	`username`	`STRING`	username for this connection to the MQTT broker
	`password`	`STRING`	password for this connection to the MQTT broker
	`useSSL`	`BOOL`	currently not supported: whether to use (`TRUE`) or not to use (`FALSE`) SSL encryption
Outputs:	`rc`	`MQTT_RC`	return code of involved MQTT functions as specified in data type `MQTT_RC`
Return value:	–	`DINT`	returns the connection handler of the newly created MQTT connection

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

See:

"Blocks for safe logic" whether this block is supported for developing safety-relevant applications.
"Highlighting safe logic in the FBD-editor" for the effects when using the block as a block for safe logic.

Example for usage within ST-editor

See "MQTT_Disconnect block".

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.