Device Twin Update

This topic is used to subscribe to device twin updates. It reflects the differences before and after a device twin update.

Topic

$hw/events/device/{device_id}/twin/update/document

Parameter	Type	Description
device_id	String	End device ID.

Usage

Use an MQTT client to subscribe to this topic.

Parameter Description

Parameter	Type	Description
event_id	String	Event ID.
timestamp	Int64	Timestamp when the event occurred.
twin	Object	A set of updated device twins. Each twin is in the key-value pair format. The value contains last (twin information before the update) and last (twin information after the update). The twin information contains the option flag, the twin metadata contains the value type, the expected status contains the expected value and update time, and the actual status contains the actual value and update time.

Example

When an end device is bound to an edge node, the following message is received:

$hw/events/device/{device_id}/twin/update/document
{
     "event_id":"",
     "timestamp":1557314742122,
     "twin":{
         "state":{
             "last":null,
             "current":{
                 "expected":{
                     "value":"running",
                     "metadata":{
                         "timestamp":1557314742122
                     }
                 },
                 "optional":true,
                 "metadata":{
                     "type":"string"
                 }
             }
         }
     }
 }