Pub

Action

String

Yes

Pub

The operation that you want to perform. Set the value to Pub.

ProductKey

String

Yes

a1Q5XoY****

The ProductKey of the product to which the device that receives the message belongs.

MessageContent

String

Yes

eyJ0ZXN0IjoidGFzayBwdWIgYnJvYWRjYXN0In0=

The body of the message that you want to publish.

To generate a message body, convert the raw message into binary data and perform Base64 encoding.

TopicFullName

String

Yes

/a1Q5XoY****/device1/user/get

The custom topic for the device that receives the message.

• If you use an MQTT gateway device, the original custom topic of the device is used as the custom topic. For more information, see Topics.

• If you use a non-MQTT gateway device, the custom topic is in one of the following formats:

  • /${productKey}/${deviceName}/user/${TopicShortName}: The system sends a message to a specific device that belongs to a product whose ProductKey is specified by the ${productKey} variable.

  • /broadcast/${productKey}/${Custom field}: The system sends a message to the online devices of a product whose ProductKey is specified by the ${productKey} variable. The online devices subscribe to the custom topic. Replace ${productKey} with the ProductKey of the product whose devices receive the message. The ${Custom field} variable specifies a custom field.

To query custom topics, use one of the following methods:

• Call the QueryProductTopic operation to query the custom topics of a product.

• On the Topic Categories tab of the details page of a product, view the custom topics of the product.

• On the Topic List tab of the details page of a device, view the custom topics to which the device subscribes.

IotInstanceId

String

No

iot-cn-0pp1n8t****

The ID of the instance. You can view the ID of the instance on the Overview page in the IoT Platform console.

For more information, see the Overview topic of IoT instances.

Qos

Integer

No

0

The quality of service (QoS) level of the message. Valid values:

• 0: The system sends the message at most once.

• 1: The system sends the message at least once. If a PUBACK response is not returned after you publish a QoS 1 message, the message is pushed to the device again when the device reconnects to IoT Platform.

Default value: 0.

For more information about messaging, see the "Device connection" section in the Limits topic.

ResponseTopic

String

No

/a1Q5XoY****/device1/user/update

The response topic in request/response communication mode when you use MQTT 5.0 for communication. For more information, see MQTT 5.0.

CorrelationData

String

No

aGVsbG8****

The related data in request/response communication mode when you use MQTT 5.0. You can configure this parameter based on your business requirements.

A message recipient can process the request based on the data.

UserProp.N.Key

String

No

key1

The custom property key that is specified when you use MQTT 5.0 for communication.

You must use this parameter together with the UserProp.N.Value parameter.

UserProp.N.Value

String

No

value1

The custom property value that is specified when you use MQTT 5.0 for communication.

You must use this parameter together with UserProp.N.Key.

DeviceName

String

No

device1

The name of the MQTT cloud gateway.

ContentType

String

No

text

The content type of the message when you use MQTT 5.0 for communication.

This parameter specifies the type of an MIME file, such as text or plain.

PayloadFormatIndicator

Integer

No

1

The payload identifier of the message when you use MQTT 5.0 for communication. Valid values:

• 0: The message is unknown byte data.

• 1: The payload of the message is character data that is encoded in UTF-8.

Retained

Boolean

No

true

Specifies whether to label the message as a retained message when you use MQTT 5.0 for communication.

• true

• false

MessageExpiryInterval

Long

No

2

The validity period of the message when you use MQTT 5.0 for communication. Unit: seconds.

• The validity period of QoS 0 messages ranges from 0 to 86,400 seconds.

• The validity period of QoS 1 messages ranges from 0 to 604,800 seconds.

TopicAlias

Integer

No

123

The topic alias that you can specify when you use MQTT 5.0 for communication. The topic alias helps reduce the communication traffic between devices and IoT Platform.

For more information about topic aliases, see Topic aliases in MQTT 5.0 features.