Device Reporting a Message

Function

If a device cannot report data in the format defined in the product model, the device can use this API to report data in a custom format to the platform. The platform does not parse the message but forwards it to an application or other Huawei Cloud services for storage and processing.

For differences between message reporting and property reporting, see Message Communications Overview.

It is not suitable to report data in JSON format for devices with low configuration and limited resources or with limits on bandwidth usage. In this case, devices can transparently transmit the original binary data to the platform, but a codec is required to convert binary data to JSON format. For details about how to develop codecs, see Developing a Codec.

Topic

Upstream: $oc/devices/{device_id}/sys/messages/up

• In addition to the preset system topics, the device can also use a custom topic that is not declared by the platform, for example, $oc/devices/{device_id}/user/{customized}.
• You can add ?request_id to the end of the topic to specify the request ID for the data reporting. Message reporting example: $oc/devices/{device_id}/sys/messages/up?request_id={request_id}. If this parameter is not specified, the platform automatically generates a request ID to identify the request.

Parameters

Message reporting has no fixed requirements on the data content. The following table lists the parameters involved when the system format is used for delivery.

IoTDA does not verify the format of the message reported by a device. The parameter description and example are for reference only. Devices can customize the data format as required.

Example

Assume that the data reported by the device is "hello!". The request examples are as follows:

• Sending only the message content:

  Topic: $oc/devices/{device_id}/sys/messages/up  
  Data format:
      hello!

• Reporting data in the system format:

  Topic: $oc/devices/{device_id}/sys/messages/up  
  Data format:
  {
      "object_device_id": "{object_device_id}",
      "name":null,
      "id":"aca6a906-c74c-4302-a2ce-b17ba2ce630c",
      "content":"hello!"
  }