You may find it necessary to deprovision devices that were previously auto-provisioned through the Device Provisioning Service.
In general, deprovisioning a device involves two steps:
1. Disenroll the device from your provisioning service, to prevent future auto-provisioning. Depending on whether you want to revoke access temporarily or permanently, you may want to either disable or delete an enrollment entry.
2. Deregister the device from your IoT Hub, to prevent future communications and data transfer. Again, you can temporarily disable or permanently delete the device's entry in the identity registry for the IoT Hub where it was provisioned.
Reference:
https://docs.microsoft.com/bs-latn-ba/azure/iot-dps/how-to-unprovision-devices

Reference:
https://docs.microsoft.com/bs-cyrl-ba/azure/iot-hub/iot-hub-message-enrichments-overview

Reference:
https://docs.microsoft.com/bs-cyrl-ba/azure/iot-hub/iot-hub-message-enrichments-overview
Topic 2, ADatum
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Requirements. Planned Changes
ADatum is developing an Azure IoT solution to monitor environmental conditions. The IoT solution consists of hardware devices and cloud services. All the devices will communicate directly to Azure IoT Hub.
The hardware devices will be deployed to the branch offices and will collect data about various environmental conditions such as temperature, humidity, air quality, and noise level. The devices will be wired by using Power over Ethernet (PoE) connections.
ADatum is developing the solution in the following three phases: proof of value (POV), pilot, and production.
Requirements. POV Requirements
The POV phase will demonstrate that a technical solution is viable. During this phase, 100 devices will be deployed to the main office and Azure Stream Analytics will be connected to an IoT hub to generate real-time alerts. Stream Analytics will perform the following processing:
Calculate the median rate of the telemetry across the entire devices that exceed the median rate by a factor of 4.
Compare the current telemetry to the specified thresholds and issue alerts when telemetry values are out of range.
Ensure that all message content during this phase is human readable to simplify debugging.
Requirements. Pilot Requirements
During the pilot phase, devices will be deployed to 10 offices. Each office will have up to 1,000 devices.
During this phase, you will add Azure Time Series Insights in parallel to Stream Analytics to support real-time graphs and queries in a dashboard web app.
The pilot deployment must minimize operating costs.
Requirements. Production Requirements
The production phase will include all the offices.
The production deployment will have one IoT hub in each Azure region. Devices must connect to the IoT hub in their region.
The production phase must meet the following requirements:
Ensure that the IoT solution can support performance and scale targets.
Ensure that the IoT solution support up to 1,000 devices per office.
Minimize operating costs of the IoT solution.
Requirements. Technical Requirements
Datum identifies the following requirements for the planned IoT solution:
The solution must generate real-time alerts when a fire condition is detected in an office. All the devices in that office must trigger an audible alarm siren within 10 seconds of the alert.
A dashboard UI must display alerts and the system status in real time and must allow device operators to make adjustments to the system.
Each device will send hourly updates to IoT Hub. Condition alerts will be sent immediately.
Multiple types of devices will collect telemetry that has different schemas.
IoT Hub must perform message routing based on the message body.
Direct methods must be used for cloud-to-device communication.
Reports must be provided monthly, quarterly, and annually.
Stored data queries must be as efficient as possible.
The device message size will be under 4 KB.
Development effort must be minimized.
Requirements. Throttle and Quotas
The relevant throttles and quotas for various IoT Hub tiers are shown in the following table.

Requirements. IoT Hub Routing
You plan to implement IoT Hub routing during the POV phase as shown in the following exhibit.

Explanation:
Step 1: From Azure IoT Hub, create an IoT Edge Device
Step 2: Deploy-IoTEdge
The Deploy-IoTEdge command checks that your Windows machine is on a supported version, turns on the containers feature, and then downloads the moby runtime and the IoT Edge runtime. The command defaults to using Windows containers.
{Invoke-WebRequest -useb https://aka.ms/iotedge-win} | Invoke-Expression; ` Deploy-IoTEdge Step 3: Initialize-IoTEdge The Initialize-IoTEdge command configures the IoT Edge runtime on your machine. The command defaults to manual provisioning with Windows containers.
{Invoke-WebRequest -useb https://aka.ms/iotedge
Step 4: Enter the IoT Edge device connection string.
When prompted, provide the device connection string that you retrieved in step 1. The device connection string associates the physical device with a device ID in IoT Hub.
Reference:
https://docs.microsoft.com/en-us/azure/iot-edge/module-composition

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 Implement Edge Question Set 1