Parameter | Type | Required | Example | Description |
Action | String | Yes | PubBroadcast | The operation that you want to perform. Set the value to PubBroadcast. |
MessageContent | String | Yes | aGVsbG93b3JsZA | The message content that you want to send. The size of a message cannot exceed 64 KB. To generate the message content, convert the raw message into binary data and perform Base64 encoding. Note IoT Platform decodes data by using the Base64 algorithm and then sends the decoded message to the device. This way, the device does not need to decode the Base64-encoded data. |
ProductKey | String | Yes | aldeji3***** | The ProductKey of the product to which the devices belong. The ProductKey is a unique identifier issued by IoT Platform to the product. You can view the information about all products within the current Alibaba Cloud account in the IoT Platform console or by calling the QueryProductList operation. |
IotInstanceId | String | No | iot_instc_pu****_c*-v64******** | The instance ID. You can view the instance ID on the Overview page in the IoT Platform console. Important If your instance has an ID, you must specify this parameter. Otherwise, the request fails. If no Overview page or ID is generated for your instance, you do not need to specify this parameter.
For more information, see Overview. |
TopicFullName | String | No | /broadcast/UPqSxj2vXXX/xxx | The topic name. If you do not specify this parameter, the message is pushed to all online devices that have the specified ProductKey. Devices receive the message from the broadcast topic in the following format: /sys/${productKey}/${deviceName}/broadcast/request/${MessageId} . The MessageId variable is generated by IoT Platform. If you specify this parameter, the message is pushed to the devices that have the specified ProductKey and subscribe to the specified topic. You must specify a broadcast topic by using the following syntax: /broadcast/${productKey}/Custom field . Replace ${productKey} with the ProductKey of the devices that receive the message. For the custom field, you can specify a value based on your business requirements.
Note When you develop devices, you need to only write code to define a broadcast topic. You do not need to create a topic in the IoT Platform console. A maximum of 1,000 devices can subscribe to a broadcast topic. If the number of devices exceeds the limit, you can divide the devices into groups. For example, you can divide 5,000 devices into 5 groups. Each group contains 1,000 devices. In this case, you must call the PubBroadcast operation five times. Each time you call the operation, set the custom field in the broadcast topic to group1, group2, group3, group4, and group5. Make sure that each group of devices subscribes to the specified broadcast topic.
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