Gateways and sub-devices

Prerequisites

• You have created a gateway and a sub-device. For more information, see Create a product and Create a device.

  • Create a product and a device for the gateway. When you create the product, set Node Type to Gateway Device.

  • Create a product and a device for the sub-device. When you create the product, set Node Type to Gateway Sub-device.

• You have completed the steps in Environment requirements and configurations and Authentication and connection.

Background information

• For more information about the sub-device feature of IoT Platform, see Gateways and sub-devices.

• For more information about the communication protocols between sub-devices and IoT Platform, see Manage topological relationships and Bring sub-devices online or take them offline.

Version requirements

Aliyun IoT Python SDK 1.2.4 or later.

API description

1. Add a sub-device topological relationship and its response callback.

   # Adds topological relationships for sub-devices in a batch and returns the request ID.
   def gateway_add_subdev_topo(self, subdevList)
   
   # The listener callback. Match the request_id in the callback with the request_id returned by gateway_add_subdev_topo.
   def on_gateway_add_subdev_topo_reply(self, request_id, code, data, msg, user_data)

2. Sub-device logon and its response callback.

   # Logs on sub-devices in a batch. 
   def gateway_login_subdev(self, subdevList)
   
   # The listener callback. Match the request_id in the callback with the request_id returned by gateway_login_subdev.
   def on_gateway_login_subdev_reply(self, request_id, code, data, msg, user_data)
   

3. Delete a sub-device topological relationship and its response callback.

   # Deletes topological relationships for sub-devices in a batch. 
   def gateway_delete_subdev_topo(self, subdevList)
   
   # The listener callback. Match the request_id in the callback with the request_id returned by gateway_delete_subdev_topo.
   def on_gateway_delete_subdev_topo_reply(self, request_id, code, data, msg, user_data)

4. Sub-device logout and its response callback.

   # Logs out sub-devices in a batch.
   def gateway_logout_subdev(self, subdevList)
   
   # The listener callback. Match the request_id in the callback with the request_id returned by gateway_logout_subdev.
   def on_gateway_logout_subdev_reply(self, request_id, code, data, msg, user_data)

5. Dynamic sub-device registration and its response callback.

   # Dynamically registers sub-devices in a batch. The productSecret is required.
   def gateway_product_register_subdev(self, subdevList)
   
   # The listener callback for the result of dynamic registration with a product. Match the request_id in the callback with the request_id returned by gateway_batch_product_register.
   def on_gateway_product_register_subdev_reply(self, request_id, code, data, msg, user_data)

6. Sub-device topological relationship change notification.

   # The listener callback for a change in the topological relationship.
   def on_gateway_topo_change(self, request_id, params, userdata)

Demo description

After the gateway is online, add a topological relationship for a sub-device and log on the sub-device. This allows the sub-device to send and receive messages. Perform the following steps in the gateway_demo.py file. You can download the demo from Environment requirements and configurations.

1. In the demo_get_subdev_list function, you can add the device certificates (ProductKey, DeviceName, and DeviceSecret) of the sub-devices to an array.

2. In the on_connect callback that is invoked after the gateway connects to IoT Platform, execute self.__linkkit.gateway_add_subdev_topo to add the topological relationship for the sub-device.

3. After the topological relationship is added, the on_gateway_add_subdev_topo_reply callback is invoked. In this callback, execute self.__linkkit.gateway_login_subdev to log on the sub-device.

4. After the sub-device logs on, the on_gateway_login_subdev_reply callback is invoked. Then, the sub-device can send and receive messages.