SubscribeMQTTMessage (FB)¶

FUNCTION_BLOCK SubscribeMQTTMessage

Function block to read C2D messages from Azure IoT Hub via MQTT.

InOut:

Scope	Name	Type	Initial	Comment
Input	xEnable	BOOL		TRUE: Subscribes C2D messages
	pbPayload	POINTER TO BYTE		Pointer to the receive buffer
	udiMaxPayloadSize	UDINT		Maximum size of the receive buffer
	eMqttQoS	MQTT_QOS	MQTT_QOS.QoS1	The QoS used in MQTT message
Inout	azureMQTTClient	AzureMQTTClient		Reference to AzureMQTTClient
Output	xError	BOOL		TRUE, if an error occurred
	xBusy	BOOL		TRUE, while the topic is subscribed
	eError	MQTT.MQTT_ERROR		Error code
	xReceived	BOOL		TRUE, if a message has been received (see |pbPayload|).
	udiPayloadSize	UDINT		Length of the received message
	xSubscribeActive	BOOL	FALSE	FALSE: When there is no active subscription, TRUE: Subscriber is listening