IoT Central Device Connection Status and Image with REST API

Question

I created a Static Web React App that connects to an IoT Central App with the REST API and lists the devices.
I want to display the connection status like it is already shown in the IoT Central, but I can't find an option where I can get the connection status for all devices.
The same goes for trying to get the image assigned to the device.

What options do I have to get the connection status and images for all devices or on a per-device basis?

Any kind of insight or help would be greatly appreciated.
Thank you in advance!

Answer 1

There is no REST API for getting a connection status of the device(s) in the IoT Central App. However, you can use the Device connectivity events in the Data export feature with a webhook destination to the Azure Event Grid custom topic as a CloudEvents message.

The following is an example of the exported CloudEvents message:

Data transformation:

if .messageSource == "deviceConnectivity" then  
{  
  specversion:"1.0",  
  id:.applicationId,  
  source: .device.id,  
  subject: ("/" + .applicationId + "/" + .device.id + "/" + .messageSource),  
  type:.messageType,  
  time:.enqueuedTime,  
  dataschema:"#",  
   data:{    
    reportedProperties: .device.properties.reported,  
    cloudProperties: .device.cloudProperties  
  }  
}  
else  
  empty  
end  

CloudEvents message:

{  
  "data":{  
    "cloudProperties":[],  
    "reportedProperties":[]  
  },  
  "dataschema":"#",  
  "id":"2922a1f6-7214-490a-88bc-a1e1d4351d12",  
  "source":"device101",  
  "specversion":"1.0",  
  "subject":"/2922a1f6-7214-490a-88bc-a1e1d4351d12/device101/deviceConnectivity",  
  "time":"2022-07-06T10:27:05.829Z",  
  "type":"disconnected"  
}  

Note, that the webhook destination header Content-Type must be configured for application/cloudevents+json

UPDATE:

I have found an undocumented REST API to get the device twin with an extended info such as the connectionState, status, modelId, etc.

  https://<applicationId>.azureiotcentral.com/system/iothub/devices/<deviceId>/get-twin?extendedInfo=true  
  Authorization: <apiToken>  

Thanks
Roman