Troubleshoot why data from your devices isn't showing up in Azure IoT Central

This document helps device developers find out why the data their devices are sending to IoT Central may not be showing up in the application.

There are two main areas to investigate:

  • Device connectivity issues
    • Authentication issues such as the device has invalid credentials
    • Network connectivity issues
    • Device isn't approved, or blocked
  • Device payload shape issues

This troubleshooting guide focuses on device connectivity issues and device payload shape issues.

Device connectivity issues

This section helps you determine if your data is reaching IoT Central.

If you haven't already done so, install the az cli tool and azure-iot extension.

To learn how to install the az cli, see Install the Azure CLI.

To install the azure-iot extension, run the following command:

az extension add --name azure-iot


You may be prompted to install the uamqp library the first time you run an extension command.

When you've installed the azure-iot extension, start your device to see if the messages it's sending are making their way to IoT Central.

Use the following commands to sign in the subscription where you have your IoT Central application:

az login
az set account --subscription <your-subscription-id>

To monitor the telemetry your device is sending, use the following command:

az iot central diagnostics monitor-events --app-id <app-id> --device-id <device-name>

If the device has connected successfully to IoT Central, you see output similar to the following:

Monitoring telemetry.
Filtering on device: device-001
    "event": {
        "origin": "device-001",
        "module": "",
        "interface": "",
        "component": "",
        "payload": {
            "temp": 65.57910343679293,
            "humid": 36.16224660107426

To monitor the property updates your device is exchanging with IoT Central, use the following preview command:

az iot central diagnostics monitor-properties --app-id <app-id> --device-id <device-name>

If the device successfully sends property updates, you see output similar to the following:

Changes in reported properties:
version : 32
{'state': 'true', 'name': {'value': {'value': 'Contoso'}, 'status': 'completed', 'desiredVersion': 7, 'ad': 'completed', 'av': 7, 'ac
': 200}, 'brightness': {'value': {'value': 2}, 'status': 'completed', 'desiredVersion': 7, 'ad': 'completed', 'av': 7, 'ac': 200}, 'p
rocessorArchitecture': 'ARM', 'swVersion': '1.0.0'}

If you see data appear in your terminal, then the data is making it as far as your IoT Central application.

If you don't see any data appear after a few minutes, try pressing the Enter or return key on your keyboard, in case the output is stuck.

If you're still not seeing any data appear on your terminal, it's likely that your device is having network connectivity issues, or is not sending data correctly to IoT Central.

Check the provisioning status of your device

If your data is not appearing on the monitor, check the provisioning status of your device by running the following command:

az iot central device registration-info --app-id <app-id> --device-id <device-name>

The following output shows an example of a device that's blocked from connecting:

  "@device_id": "v22upeoqx6",
  "device_registration_info": {
    "device_status": "blocked",
    "display_name": "Environmental Sensor - v22upeoqx6",
    "id": "v22upeoqx6",
    "instance_of": "urn:krhsi_k0u:modelDefinition:w53jukkazs",
    "simulated": false
  "dps_state": {
    "error": "Device is blocked from connecting to IoT Central application. Unblock the device in IoT Central and retry. Learn more:",
    "status": null
Device provisioning status Description Possible mitigation
Provisioned No immediately recognizable issue. N/A
Registered The device has not yet connected to IoT Central. Check your device logs for connectivity issues.
Blocked The device is blocked from connecting to IoT Central. Device is blocked from connecting to the IoT Central application. Unblock the device in IoT Central and retry. To learn more, see Block devices.
Unapproved The device is not approved. Device isn't approved to connect to the IoT Central application. Approve the device in IoT Central and retry. To learn more, see Approve devices
Unassociated The device is not associated with a device template. Associate the device with a device template so that IoT Central knows how to parse the data.

Learn more about device status codes.

Error codes

If you're still unable to diagnose why your data isn't showing up in monitor-events, the next step is to look for error codes reported by your device.

Start a debugging session on your device, or collect logs from your device. Check for any error codes that the device reports.

The following tables show the common error codes and possible actions to mitigate.

If you are seeing issues related to your authentication flow:

Error code Description Possible Mitigation
400 The body of the request is not valid. For example, it cannot be parsed, or the object cannot be validated. Ensure that you're sending the correct request body as part of the attestation flow, or use a device SDK.
401 The authorization token cannot be validated. For example, it has expired or doesn't apply to the request's URI. This error code is also returned to devices as part of the TPM attestation flow. Ensure that your device has the correct credentials.
404 The Device Provisioning Service instance, or a resource such as an enrollment doesn't exist. File a ticket with customer support.
412 The ETag in the request doesn't match the ETag of the existing resource, as per RFC7232. File a ticket with customer support.
429 Operations are being throttled by the service. For specific service limits, see IoT Hub Device Provisioning Service limits. Reduce message frequency, split responsibilities among more devices.
500 An internal error occurred. File a ticket with customer support to see if they can help you further.

File upload error codes

Here is a list of common error codes you might see when a device tries to upload a file to the cloud. Remember that before your device can upload a file, you must configure device file uploads in your application.

Error code Description Possible Mitigation
403006 You've exceeded the number of concurrent file upload operations. Each device client is limited to 10 concurrent file uploads. Ensure the device promptly notifies IoT Central that the file upload operation has completed. If that doesn't work, try reducing the request timeout.

Payload shape issues

When you've established that your device is sending data to IoT Central, the next step is to ensure that your device is sending data in a valid format.

There are two main categories of common issues that cause device data to not appear in IoT Central:

  • Device template to device data mismatch:
    • Mismatch in naming such as typos or case-matching issues.
    • Unmodeled properties where the schema isn't defined in the device template.
    • Schema mismatch such as a type defined in the template as boolean, but the data is a string.
    • The same telemetry name is defined in multiple interfaces, but the device isn't IoT Plug and Play compliant.
  • Data shape is invalid JSON. To learn more, see Telemetry, property, and command payloads.

To detect which categories your issue is in, run the most appropriate command for your scenario:

  • To validate telemetry, use the preview command:

    az iot central diagnostics validate-messages --app-id <app-id> --device-id <device-name>
  • To validate property updates, use the preview command

    az iot central diagnostics validate-properties --app-id <app-id> --device-id <device-name>

You may be prompted to install the uamqp library the first time you run a validate command.

The following output shows example error and warning messages from the validate command:

Validating telemetry.
Filtering on device: v22upeoqx6.
Exiting after 300 second(s), or 10 message(s) have been parsed (whichever happens first).
[WARNING] [DeviceId: v22upeoqx6] No encoding found. Expected encoding 'utf-8' to be present in message header.

[WARNING] [DeviceId: v22upeoqx6] Content type '' is not supported. Expected Content type is 'application/json'.

[ERROR] [DeviceId: v22upeoqx6] [TemplateId: urn:krhsi_k0u:modelDefinition:w53jukkazs] Datatype of field 'humid' does not match the da
tatype 'double'. Data '56'. All dates/times/datetimes/durations must be ISO 8601 compliant.

If you prefer to use a GUI, use the IoT Central Raw data view to see if something isn't being modeled. The Raw data view doesn't detect if the device is sending malformed JSON.

Screenshot of Raw Data view

When you've detected the issue, you may need to update device firmware, or create a new device template that models previously unmodeled data.

If you chose to create a new template that models the data correctly, migrate devices from your old template to the new template. To learn more, see Manage devices in your Azure IoT Central application.

Next steps

If you need more help, you can contact the Azure experts on the MSDN Azure and Stack Overflow forums. Alternatively, you can file an Azure support ticket.

For more information, see Azure IoT support and help options.