AWSIoTSubscribe (FB)¶

FUNCTION_BLOCK AWSIoTSubscribe

Function block to subscribe a topic.

InOut:

Scope	Name	Type	Initial	Comment
Input	`xEnable`	`BOOL`		TRUE: Subscribes a topic (see \|wsTopicFilter\|), FALSE: Unsubscribe
	`pbPayload`	POINTER TO BYTE		Pointer to the receive buffer
	`udiMaxPayloadSize`	`UDINT`		Maximum size of the receive buffer
	`eQoS`	QOS		Quality of service level (QoS)
	`mQTTSubscribeProperties`	REFERENCE TO MQTTSubscribeProperties		Subscribe proerties (MQTT V5 only)
	`udiTimeout`	`UDINT`	1000000	Time in µs in which an subcription acknowledgement (SUBACK) must be received.
Inout	`awsIoTClient`	AWSIoTClient		Reference to AWSIoTClient
Inout	`wsTopicFilter`	`WSTRING(1024)`		Reference to the topic filter (‘+’ and ‘#’ are allowed)
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
	`wsLastTopic`	`WSTRING(1024)`		Last received topic
	`mQTTPublishProperties`	MQTTPublishProperties		Last received publish properties (MQTT V5 only)