Help Center> IoT Device Access> API Reference> MQTT or MQTTS API Reference on the Device Side> Software and Firmware Upgrade> Platform Delivering an Event to Obtain Version Information
Updated on 2023-02-16 GMT+08:00
View PDF

Platform Delivering an Event to Obtain Version Information

Function

This API is used by the platform to deliver an event to obtain version information.

Topic

Downstream: $oc/devices/{device_id}/sys/events/down

Parameters

Parameter

Mandatory or Optional

Type

Description

object_device_id

Optional

String

Indicates the device that the event is about. If this parameter is not carried, the device specified in the topic is considered to be the device involved.

services

Optional

List<ServiceEvent>

Indicates a list of services that the event is about.

ServiceEvent structure

Parameter

Mandatory or Optional

Type

Description

service_id

Mandatory

String

System field. The value is fixed to $ota.

event_type

Mandatory

String

System field. The value is fixed to version_query.

event_time

Optional

String

Indicates the time when the event occurs.

paras

Optional

Object

Indicates the JSON object of the event parameter. No specific field is delivered when the event to obtain version information is delivered.

Example

Topic: $oc/devices/{device_id}/sys/events/down  
Data format:
{ 
    "object_device_id": "{object_device_id}", 
    "services": [{ 
        "service_id": "$ota", 
        "event_type": "version_query", 
        "event_time": "20151212T121212Z",
         "paras": { 
         } 
    }] 
}