AWSIoTSubscribeDeviceShadow (FB)

FUNCTION_BLOCK AWSIoTSubscribeDeviceShadow

Function block to subscribe for changes of the device shadow.

InOut:

Scope

Name

Type

Initial

Comment

Input

xEnable

BOOL

TRUE: Subscribes device shadow changes, FALSE: Unsubscribe

pbPayload

POINTER TO BYTE

Pointer to the receive buffer (device shadow delta)

udiMaxPayloadSize

UDINT

Maximum size of the receive buffer

eQoS

QOS

Quality of service level (QoS)

sClientId

REFERENCE TO STRING(255)

0

The name of another thing. The input sClientId can be used to access device shadows of other things. if 0, then the clientId from AWSIoTClient will be used.

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

Output

xError

BOOL

TRUE, if an error occurred

xBusy

BOOL

TRUE, while is subscribed

eError

MQTT.MQTT_ERROR

Error code

xReceived

BOOL

TRUE, if the device shadow has been changed

xSubscribeActive

BOOL

FALSE

FALSE: When there is no active subscription, TRUE: Subscriber is listening

udiPayloadSize

UDINT

Length of the device shadow delta

mQTTPublishProperties

MQTTPublishProperties

Last received publish properties