MQTT_ReadTopicString (FUN)

FUNCTION MQTT_ReadTopicString : WORD

This function subscribes to the specified MQTT topic and returns published messages as strings.

The output valid is set to TRUE when a publication occurs on the topic and the message payload is copied into value.

InOut:

Scope	Name	Type	Comment
Return	MQTT_ReadTopicString	WORD	Status code returned by the runtime (0 means "no errors").
Inout	id	WORD	Operation identifier used by the runtime.
Input	topic	STRING(127)	MQTT topic name.
	qos	WORD	Quality of Service level.
Output	value	STRING(244)	String value received from the topic.
	valid	BOOL	TRUE when a valid value has been received.