Azure IoT Central - Not generating a device template for Plug and Play device

Question

Azure IoT Central - Not generating a device template for Plug and Play device

Anonymous

I've been working on adding IoT Hub Plug and Play support for our development kit, the Avnet Azure Sphere Starter Kit. I've made good progress and today my DTDL model was merged into the Microsoft Plug and Play repository.

I've verified that my application is working correctly by leveraging the Azure IoT Explorer application. Using this application and connecting my device to an IoT Hub, I verified that Azure IoT Explorer can resolve my model ID "dtmi:avnet:Starterkit;1," and pull the model into the application. In the Azure IoT Explorer I configured the tool to only look for my model in the public repo "https://devicemodels.azure.com."

Since this is working in the Azure IoT Explorer tool I assume that the following statements are true:

My device model is valid
The Model ID my application is sending to the IoT Hub is correct, IoT Explorer is pulling the model from the public repo

Next, I wanted to test my Plug and Play device in IoT Central. I created an IoT Central Application and configured my application to connect to my new application.

My device connects, I can see the device ID under the Devices --> All devices list

I was expecting that IoT Central would use the model ID to pull my model from the public repo and create a device template that matched my model, then automatically move the device into the new device template. However, I don't see any device templates in my application, even after my device connects, and I approved the device.

I looked at the IoT Central documentation and found this statement: "Implement your device code from the model, and connect your real device to your IoT Central application. IoT Central finds and imports the device model from the public repository for you and generates a device template. "

This feature does not appear to be working, can you help me troubleshoot the issue?

Thanks,

Brian

AshokPeddakotla-MSFT 36,021 Reputation points Moderator

2021-01-05T10:17:34.267+00:00

@Anonymous Community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.
Roman Kiss 2,246 Reputation points

2021-01-05T12:25:50.923+00:00

Hi Brian,

how your model validation (dtmi:dtdl:context;2) has been passed for unit, for example at the gX property, where an unit is "mg":

{
"@type ": [
"Telemetry",
"gX"
],
"displayName": {
"en": "Acceleration X Axis"
},
"name": "gX",
"schema": "float",
"unit": "mg"
},

when I tried to insert your model 'dtmi:avnet:Starterkit;1' to the IoT Central App, I have received many errors about the unit validation.

Note, that the unit property has been replaced with a sematic unit in the version 2

Thanks
Roman
Anonymous

2021-01-05T12:48:21.837+00:00

Hi Roman,

Thanks for the response. What's the best method/process to validate my changes?

I'll need to go through the Pull Request process again, and I would like to be able to verify that I have everything working correctly the first time.

Brian
Roman Kiss 2,246 Reputation points

2021-01-05T13:43:27.04+00:00

Hi Brian,

the quick way to make your changes in the device model is using the IoT Central App with generated an error list, then walk through this error list and fix your properties in the model, for example:

{
"@type ": [
"Property",
"Frequency"
],
"displayName": {
"en": "Frequency"
},
"name": "freq",
"schema": "integer",
"unit": "megahertz",
"writable": false
},

As you can see the above "@type " and unit properties must be matched with the DTDL version 2 spec. Note, the the value is case sensitive.

Thanks
Roman

Answer accepted by question author

0 additional answers

Your answer

AshokPeddakotla-MSFT 36,021 Reputation points Moderator

2021-01-05T10:17:34.267+00:00

@Anonymous Community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.
Roman Kiss 2,246 Reputation points

2021-01-05T12:25:50.923+00:00

Hi Brian,

how your model validation (dtmi:dtdl:context;2) has been passed for unit, for example at the gX property, where an unit is "mg":

{
"@type ": [
"Telemetry",
"gX"
],
"displayName": {
"en": "Acceleration X Axis"
},
"name": "gX",
"schema": "float",
"unit": "mg"
},

when I tried to insert your model 'dtmi:avnet:Starterkit;1' to the IoT Central App, I have received many errors about the unit validation.

Note, that the unit property has been replaced with a sematic unit in the version 2

Thanks
Roman
Anonymous

2021-01-05T12:48:21.837+00:00

Hi Roman,

Thanks for the response. What's the best method/process to validate my changes?

I'll need to go through the Pull Request process again, and I would like to be able to verify that I have everything working correctly the first time.

Brian
Roman Kiss 2,246 Reputation points

2021-01-05T13:43:27.04+00:00

Hi Brian,

the quick way to make your changes in the device model is using the IoT Central App with generated an error list, then walk through this error list and fix your properties in the model, for example:

{
"@type ": [
"Property",
"Frequency"
],
"displayName": {
"en": "Frequency"
},
"name": "freq",
"schema": "integer",
"unit": "megahertz",
"writable": false
},

As you can see the above "@type " and unit properties must be matched with the DTDL version 2 spec. Note, the the value is case sensitive.

Thanks
Roman

Answer 1

Roman,

Thanks for the help. I've made good progress today . . .

I've cleaned up my model and it imports into IoT Central without any errors
I've uploaded the new model to the public repo as rev2
Using the Azure IoT Explorer tool I verified that I can . . .
- See all my read only properties
- Exercise all my write/read properties
- Exercise my direct methods
- See all my telemetry as "modeled events"

Next I configured my device to connect to my IoT Central Application

I deleted my device
I deleted any device templates
Started my device
- It connects to my IoT Central application
- A device template is automatically created!
- I drill down into my device
- I can see the default "views"
- I don't see any telemetry on the overview view
  - I look at the Raw data view and I can see my telemetry coming in, however it's identified as "Unmodeled data"
  - I'm sending the telemetry as simple key: value JSON
  - The telemetry is being correctly identified as modeled data in the Azure IoT Explorer tools
- I looked at the documentation and it states . . .

Telemetry
Telemetry sent from a no component device doesn't require any extra metadata. The system > adds the dt-dataschema property.

>

Telemetry sent from a multiple component device must add $.sub as a message property. The > system adds the dt-subject and dt-dataschema properties.

Looking at my telemetry, I can see that the dt-dataschema systemProperty is set.

{
"body": {
"gX": 0,
"gY": -0.02,
"gZ": 1.01,
"aX": 0,
"aY": -0.07,
"aZ": 0,
"pressure": 1011.8,
"light_intensity": 0,
"altitude": 12.08,
"temp": 32.82,
"rssi": -36
},
"enqueuedTime": "2021-01-05T20:48:36.425Z",
"systemProperties": {
"iothub-connection-device-id": "cb9143742fbdc70708369758ef98654c7e8b2a6ae519030e7b6e9be0480dbb01ab084a54aef1819a1fbd991016700f025b4dcd92fb1a2a8e40666db52223cb6f",
"iothub-connection-auth-method": "{\"scope\":\"device\",\"type\":\"x509Certificate\",\"issuer\":\"external\",\"acceptingIpFilterRule\":null}",
"iothub-connection-auth-generation-id": "637438387425275525",
"iothub-enqueuedtime": 1609879716206,
"iothub-message-source": "Telemetry",
"dt-dataschema": "dtmi:avnet:Starterkit;2",
"x-opt-sequence-number": 248640,
"x-opt-offset": "163208842184",
"x-opt-enqueued-time": 1609879716425
}
}

Any idea why my telemetry is not seen as "modeled" data in IoT Central?

Thanks,

Brian

Roman Kiss 2,246 Reputation points

2021-01-06T09:43:17.033+00:00

Hi Brian,

I have inserted your updated device model version 2 into the IoT Central App and provisioned the device from my simulator tester Azure IoT Hub Tester:

as you can see the Topic's property $.sub represents the component name, where for default component such as your case can be empty ($.sub=), null ($.sub) or not exist. In my test is null.

The following screen snippet shows a Raw data on the IoT Central App:

As you can see, the telemetry data have been processed as a modelled data, so try to add to the topic the null property $.sub, it looks like the problem can be on the Azure IoT Explorer tool.

Thanks
Roman
Roman Kiss 2,246 Reputation points

2021-01-06T10:06:15.61+00:00

In addition to my comment:

The IoT Central App didn't modify a device model (version 2) when the command is sync or async (based on the selection of the Queue if offline) , see the following screen snippet:

Based on the device model, the IoT Central App will generate a direct method (such as a sync command) to the device, but the device during the design time can not properly created a logic (such as subscribing, etc.) and when the response is not required, the device will expected a C2D message instead of direct method.

Therefore, I do recommend to add the response to the command, for instance: simple returned text "Done".

You can see this difference in my tester when the IoT Central App fired both commands. The device model expected two C2D messages, but the IoTC App invoked the direct method on the device.

Thanks
Roman
Anonymous

2021-01-06T12:06:40.73+00:00

Hi Roman,

The telemetry is working now. I did not make any changes to my application. If I look at the Raw Data history, yesterday evening sometimes the message was properly decoded and sometimes it was not (same exact messages). Now all messages are being correctly identified as modeled data.

I have another issue with my model and IoT Central, but I'll start a new thread on that issue.

You've been very helpful, and I appreciate your help and your time, Thank You!

Brian