Topic Overview

To make it easier for the cloud platform to apply different processing strategies for properties of different natures, the Thing Model properties reported by devices are divided into two categories, osd and state, which are reported on different topics.

• osd: Properties reported by the device at a fixed frequency, corresponding to pushmode = 0.
• state: Thing Model properties reported by the device on an event basis, corresponding to pushmode=1.

Note: In the table below, {gateway_sn} indicates the SN of the gateway device, and {device_sn} indicates the SN of the device to which the Thing Model property belongs.

Topic Name	Sender -> Subscriber	Message	Description
thing/product/{device_sn}/osd	Device > Cloud platform	osd message struct	Device properties (properties) pushed by the device to the cloud platform at a fixed frequency. For the specific content scope, see the Thing Model content.
thing/product/{device_sn}/state	Device > Cloud platform	state message struct	Device properties (properties) pushed by the device to the cloud platform on demand. For the specific content scope, see the Thing Model content.
thing/product/{gateway_sn}/services	Cloud platform -> Device	services message struct	Services sent by the cloud platform to the device (for the specific service identifier, see the Thing Model content).
thing/product/{gateway_sn}/services_reply	Device > Cloud platform	services_reply message struct	The device's reply to the service and the processing result.
thing/product/{gateway_sn}/events	Device > Cloud platform	events message struct	Events that require attention and handling, sent by the device to the cloud platform. For example, the SD card is full, the aircraft is unlocked in a no-fly zone, and so on (for the event scope, see the Thing Model content).
thing/product/{gateway_sn}/events_reply	Cloud platform -> Device	events_reply message struct	The cloud platform's reply to the device event and the processing result.
thing/product/{gateway_sn}/requests	Device > Cloud platform	requests message struct	Requests sent by the device to the cloud platform to obtain information, such as a temporary credential for uploading.
thing/product/{gateway_sn}/requests_reply	Cloud platform -> Device	requests_reply message struct	The cloud platform's reply to the device request.
sys/product/{gateway_sn}/status	Device > Cloud platform	status message struct	Device online/offline and topology update.
sys/product/{gateway_sn}/status_reply	Cloud platform -> Device	status_reply message struct	Platform response.
thing/product/{gateway_sn}/property/set	Cloud platform -> Device	property set message struct	Device Property Set. Whether a device property can be modified is determined by the "accessMode" identifier in the device property section; accessMode = rw indicates that it can be read and written.
thing/product/{gateway_sn}/property/set_reply	Device > Cloud platform	property set_reply message struct	Response to the device property set.
thing/product/{gateway_sn}/drc/up	Device > Cloud platform	DRC message struct	DRC protocol uplink.
thing/product/{gateway_sn}/drc/down	Cloud platform > Device	DRC message struct	DRC protocol downlink.

Common Field Descriptions

Column	Name	Type	Description
tid	Transaction uuid	text	The UUID of a Transaction: represents a single simple message communication, such as create/delete/update/query, gimbal control, etc. It can be: 1. A data report request + a data report response 2. A handshake authentication request + response + ack 3. A one-way notification of an alarm event, etc. It solves the problems of transaction concurrency and message matching.
bid	Business uuid	text	The UUID of a Business: some functions cannot be completed in a single communication and include all interactions over a period of time. A business is usually composed of multiple atomic transactions and lasts a relatively long time; for example, on-demand playback/download/replay. It solves the problems of business concurrency and duplicate requests, and facilitates state-machine management for all modules.
timestamp	Millisecond timestamp	int	The time the message was sent
gateway	Serial number of the gateway device	text	The serial number of the gateway device that sent this message
data	Message content	object	Message content

osd Struct Example

topic: thing/product/{device_sn}/osd

{
  "tid": "65717bf1-aee7-4abb-8ea3-9b1908548d74",
  "bid": "cf5ad2e6-2f32-4b59-980e-d5c9ee412805",
  "timestamp": 1667220873846,
  "data": {
    "job_number": 492,
    "acc_time": 1859010,
    "activation_time": 0,
    "maintain_status": {
      "maintain_status_array": [
        {
          "state": 0,
          "last_maintain_type": 17,
          "last_maintain_time": 0,
          "last_maintain_work_sorties": 0
        }
      ]
    },
    "electric_supply_voltage": 231,
    "working_voltage": 25440,
    "working_current": 1120,
    "backup_battery": {
      "voltage": 26631,
      "temperature": 27.9,
      "switch": 1
    },
    "drone_battery_maintenance_info": {
      "maintenance_state": 0,
      "maintenance_time_left": 0
    }
  },
  "gateway": "dock_sn"
}

{
  "bid": "d6cfcea4-c6ca-439b-948f-b17d88fc308f",
  "data": {
    "flighttask_step_code": 255,
    "media_file_detail": {
      "remain_upload": 0
    },
    "wireless_link": {
      "4g_freq_band": 2.4,
      "4g_gnd_quality": 0,
      "4g_link_state": 0,
      "4g_quality": 0,
      "4g_uav_quality": 0,
      "dongle_number": 0,
      "link_workmode": 0,
      "sdr_freq_band": 2.4,
      "sdr_link_state": 0,
      "sdr_quality": 0
    }
  },
  "tid": "e4c15182-776b-4c13-9973-3fc76848ca15",
  "timestamp": 1667220881576,
  "gateway": "dock_sn"
}

{
  "tid": "43d2e632-1558-4c4e-83d2-eeb51b7a377a",
  "bid": "7578f2ac-1f12-4d47-9ab6-5de146ed7b8a",
  "timestamp": 1667220916697,
  "data": {
    "network_state": {
      "type": 2,
      "quality": 0,
      "rate": 5.0970001220703125
    },
    "drone_charge_state": {
      "state": 0,
      "capacity_percent": 100
    },
    "drone_in_dock": 1,
    "rainfall": 0,
    "wind_speed": 0,
    "environment_temperature": 24,
    "temperature": 24.9,
    "humidity": 62,
    "latitude": 22.907809968,
    "longitude": 113.703482143,
    "height": 34.17412567138672,
    "alternate_land_point": {
      "latitude": 22.90789831990866,
      "longitude": 113.70347329676635,
      "safe_land_height": 0,
      "is_configured": 1
    },
    "first_power_on": 1631945855969,
    "position_state": {
      "is_calibration": 1,
      "is_fixed": 2,
      "quality": 5,
      "gps_number": 6,
      "rtk_number": 25
    },
    "storage": {
      "total": 82045336,
      "used": 51772
    },
    "mode_code": 1,
    "cover_state": 0,
    "supplement_light_state": 0,
    "emergency_stop_state": 0,
    "air_conditioner_mode": 0,
    "battery_store_mode": 1,
    "alarm_state": 0,
    "putter_state": 0,
    "sub_device": {
      "device_sn": "1581F5BKD225D00BP891",
      "device_model_key": "0-67-0",
      "device_online_status": 0,
      "device_paired": 1
    }
  },
  "gateway": "dock_sn"
}

state Struct Example

topic: thing/product/{device_sn}/state

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "data": {}
}

services Struct Example

topic: thing/product/{gateway_sn}/services

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "method": "some_method",
  "data": {}
}

services_reply Struct Example

Required fields in data

Column	Name	Type	constraint	Description
result	Result code of the device response	int		Non-zero indicates an error
output	Device message content	struct		The message content of the device's response to the server command

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "method": "some_method",
  "data": {
    "result": 0,
    "output": {}
  }
}

events Struct Example

topic: thing/product/{gateway_sn}/events

Column	Name	Type	constraint	Description
need_reply	Whether the server needs to reply	int		After the server receives the device's events report message, it uses need_reply to determine whether to send a receipt reply; 0 means not needed, 1 means needed

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "need_reply": 0,
  "gateway": "sn",
  "method": "some_method",
  "data": {}
}

events_reply Struct Example

topic: thing/product/{gateway_sn}/events_reply

Required fields in data

Column	Name	Type	constraint	Description
result	Result code of the server response	int		Non-zero indicates an error

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "method": "some_method",
  "data": {
    "result": 0
  }
}

requests Struct Example

topic: thing/product/{gateway_sn}/requests

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "method": "some_method",
  "data": {}
}

requests_reply Struct Example

topic: thing/product/{gateway_sn}/requests_reply

Required fields in data

Column	Name	Type	constraint	Description
result	Result code of the server response	int		Non-zero indicates an error
output	Service message content	struct		The message content of the server's response to the device

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "gateway": "sn",
  "method": "some_method",
  "data": {
    "result": 0,
    "output": {}
  }
}

status Struct Example

topic: sys/product/{gateway_sn}/status

Gateway device and sub-device online

{
  "tid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx",
  "bid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx",
  "method": "update_topo",
  "timestamp": 1234567890123,
  "data": {
    "type": 98,
    "sub_type": 0,
    "device_secret": "secret",
    "nonce": "nonce",
    "version": 1,
    "sub_devices": [
      {
        "sn": "drone001",
        "type": 116,
        "sub_type": 0,
        "index": "A",
        "device_secret": "secret",
        "nonce": "nonce",
        "version": 1
      }
    ]
  }
}

Sub-device offline

{
  "tid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx",
  "bid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx",
  "method": "update_topo",
  "timestamp": 1234567890123,
  "data": {
    "type": 98,
    "sub_type": 0,
    "device_secret": "secret",
    "nonce": "nonce",
    "version": 1,
    "sub_devices": []
  }
}

status_reply Struct Example

topic: sys/product/{gateway_sn}/status_reply

Required fields in data

Column	Name	Type	constraint	Description
result	Result code	int		Non-zero indicates an error

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "method": "update_topo",
  "data": {
    "result": 0
  }
}

property set Struct Example

topic: thing/product/{gateway_sn}/property/set

Column	Name	Type	constraint	Description
some_property	The key of the property to be modified	string		See Device Management Whether a device property can be modified is determined by the "accessMode" identifier in the device property section; accessMode = rw indicates that it can be read and written.
some_value	The value of the property to be modified	string/int/float		See the corresponding device property

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "data": {
    "some_property": "some_value"
  }
}

property set_reply Struct Example

topic: thing/product/{gateway_sn}/property/set_reply

Required fields in data

Column	Name	Type	constraint	Description
some_property	The key of the property to be modified	string		See Device Management Whether a device property can be modified is determined by the "accessMode" identifier in the device property section; accessMode = rw indicates that it can be read and written.
result	The setting result of the corresponding property	int		0: success, 1: failure, 2: timeout; for others, see the error code descriptions

{
  "tid": "6a7bfe89-c386-4043-b600-b518e10096cc",
  "bid": "42a19f36-5117-4520-bd13-fd61d818d52e",
  "timestamp": 1598411295123,
  "data": {
    "some_property": {
      "result": 0
    }
  }
}

drc up Struct Example

topic: thing/product/{gateway_sn}/drc/up

Required fields in data

Column	Name	Type	constraint	Description
result	Result code of the server response	int		Non-zero indicates an error
output	Service message content	struct		The message content of the server's response to the device

{
  "method": "drone_control",
  "data": {
    "result": 0,
    "output": {
      "seq": 1
    }
  }
}

drc down Struct Example

topic: thing/product/{gateway_sn}/drc/down

{
  "method": "drone_control",
  "data": {
    "seq": 1,
    "x": 2.34,
    "y": -2.45,
    "h": 2.76,
    "w": 2.86
  }
}