An enrollment is the record of devices or groups of devices that may register through auto-provisioning. The enrollment record contains information about the device or group of devices, including:
* the attestation mechanism used by the device
* the optional initial desired configuration
* desired IoT hub
the desired device ID
Note: Azure IoT auto-provisioning can be broken into three phases:
1. Service configuration - a one-time configuration of the Azure IoT Hub and IoT Hub Device Provisioning Service instances, establishing them and creating linkage between them.
2. Device enrollment - the process of making the Device Provisioning Service instance aware of the devices that will attempt to register in the future. Enrollment is accomplished by configuring device identity information in the provisioning service, as either an "individual enrollment" for a single device, or a "group enrollment" for multiple devices.
3. Device registration and configuration
Reference:
https://docs.microsoft.com/en-us/azure/iot-dps/concepts-service#enrollment

Devices use telemetry to send numerical data from the device. A rule triggers when the selected telemetry crosses a specified threshold.
E: To create a telemetry rule, the device template must include at least one telemetry value. The rule monitors the temperature reported by the device and sends an email when it falls below 400 degrees.
B: Configure the rule conditions.
Conditions define the criteria that the rule monitors. In this tutorial, you configure the rule to fire when the temperature exceeds 70°F.
1. Select Temperature in the Telemetry dropdown.
2. Next, choose Is less than as the Operator and enter 400 as the Value.

3. Optionally, you can set a Time aggregation. When you select a time aggregation, you must also select an aggregation type, such as average or sum from the aggregation drop-down.
Without aggregation, the rule triggers for each telemetry data point that meets the condition.
With aggregation, the rule triggers if the aggregate value of the telemetry data points in the time window meets the condition.
Reference:
https://docs.microsoft.com/en-us/azure/iot-central/core/tutorial-create-telemetry-rules

Explanation
Text Description automatically generated with low confidence

Box 1: 1
A priority defines whether a deployment should be applied to a targeted device relative to other deployments.
A deployment priority is a positive integer, with larger numbers denoting higher priority. If an IoT Edge device is targeted by more than one deployment, the deployment with the highest priority applies.
Deployments with lower priorities are not applied, nor are they merged. If a device is targeted with two or more deployments with equal priority, the most recently created deployment (determined by the creation timestamp) applies.
Box 2: "properties.tags": {
You create a deployment manifest and then define which devices it applies to based on tags in the device twin.
Reference:
https://docs.microsoft.com/en-us/azure/iot-edge/module-deployment-monitoring

IoT Hub provides three options for device apps to expose functionality to a back-end app:
* Twin's desired properties for long-running commands intended to put the device into a certain desired state.
For example, set the telemetry send interval to 30 minutes.
* Direct methods for communications that require immediate confirmation of the result. Direct methods are often used for interactive control of devices such as turning on a fan.
* Cloud-to-device messages for one-way notifications to the device app.
Reference:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-c2d-guidance

Explanation:
Step: With DPS (Device Provisioning Service) you can generate device credentials and configure the devices offline without registering the devices through IoT Central UI.
Connect devices that use SAS tokens without registering
1. Copy the IoT Central application's group primary key
2. Use the dps-keygen tool to generate the device SAS keys. Use the group primary key from the previous step. The device IDs must be lower-case:
dps-keygen -mk:<group primary key> -di:<device ID>
3. The OEM flashes each device with a device ID, a generated device SAS key, and the application ID scope value.
4. When you switch on a device, it first connects to DPS to retrieve its IoT Central registration information.
The device initially has a device status Unassociated on the Devices page and isn't assigned to a device template. On the Devices page, Migrate the device to the appropriate device template. Device provisioning is now complete, the device status is now Provisioned, and the device can start sending data.
On the Administration > Device connection page, the Auto approve option controls whether you need to manually approve the device before it can start sending data.
Reference:
https://docs.microsoft.com/en-us/azure/iot-central/core/concepts-get-connected