Remote monitoring preconfigured solution walkthrough

Introduction

The IoT Suite remote monitoring preconfigured solution is an implementation of an end-to-end monitoring solution for multiple machines running in remote locations. The solution combines key Azure services to provide a generic implementation of the business scenario and you can use it as a starting point for your own implementation. You can customize the solution to meet your own specific business requirements.

This article walks you through some of the key elements of the remote monitoring solution to enable you to understand how it works. This knowledge helps you to:

  • Troubleshoot issues in the solution.
  • Plan how to customize to the solution to meet your own specific requirements.
  • Design your own IoT solution that uses Azure services.

Logical architecture

The following diagram outlines the logical components of the preconfigured solution:

Logical architecture

Simulated devices

In the preconfigured solution, the simulated device represents a cooling device (such as a building air conditioner or facility air handling unit). When you deploy the preconfigured solution, you also automatically provision four simulated devices that run in an Azure WebJob. The simulated devices make it easy for you to explore the behavior of the solution without the need to deploy any physical devices. To deploy a real physical device, see the Connect your device to the remote monitoring preconfigured solution tutorial.

Each simulated device can send the following message types to IoT Hub:

Message Description
Startup When the device starts, it sends a device-info message containing information about itself to the back end. This data includes the device id, the device metadata, a list of the commands the device supports, and the current configuration of the device.
Presence A device periodically sends a presence message to report whether the device can sense the presence of a sensor.
Telemetry A device periodically sends a telemetry message that reports simulated values for the temperature and humidity collected from the device's simulated sensors.

The simulated devices send the following device properties in a device-info message:

Property Purpose
Device ID Id that is either provided or assigned when a device is created in the solution.
Manufacturer Device manufacturer
Model Number Model number of the device
Serial Number Serial number of the device
Firmware Current version of firmware on the device
Platform Platform architecture of the device
Processor Processor running the device
Installed RAM Amount of RAM installed on the device
Hub Enabled State IoT Hub state property of the device
Created Time Time the device was created in the solution
Updated Time Last time properties were updated for the device
Latitude Latitude location of the device
Longitude Longitude location of the device

The simulator seeds these properties in simulated devices with sample values. Each time the simulator initializes a simulated device, the device posts the pre-defined metadata to IoT Hub. Note how this overwrites any metadata updates made in the device portal.

The simulated devices can handle the following commands sent from the solution dashboard through the IoT hub:

Command Description
PingDevice Sends a ping to the device to check it is alive
StartTelemetry Starts the device sending telemetry
StopTelemetry Stops the device from sending telemetry
ChangeSetPointTemp Changes the set point value around which the random data is generated
DiagnosticTelemetry Triggers the device simulator to send an additional telemetry value (externalTemp)
ChangeDeviceState Changes an extended state property for the device and sends the device info message from the device

The device command acknowledgment to the solution back end is provided through the IoT hub.

IoT Hub

The IoT hub ingests data sent from the devices into the cloud and makes it available to the Azure Stream Analytics (ASA) jobs. IoT hub also sends commands to your devices on behalf of the device portal. Each stream ASA job uses a separate IoT Hub consumer group to read the stream of messages from your devices.

Azure Stream Analytics

In the remote monitoring solution, Azure Stream Analytics (ASA) dispatches device messages received by the IoT hub to other back-end components for processing or storage. Different ASA jobs perform specific functions based on the content of the messages.

Job 1: Device Info filters device information messages from the incoming message stream and sends them to an Event Hub endpoint. A device sends device information messages at startup and in response to a SendDeviceInfo command. This job uses the following query definition to identify device-info messages:

SELECT * FROM DeviceDataStream Partition By PartitionId WHERE  ObjectType = 'DeviceInfo'

This job sends its output to an Event Hub for further processing.

Job 2: Rules evaluates incoming temperature and humidity telemetry values against per-device thresholds. Threshold values are set in the rules editor available in the solution dashboard. Each device/value pair is stored by timestamp in a blob which Stream Analytics reads in as Reference Data. The job compares any non-empty value against the set threshold for the device. If it exceeds the '>' condition, the job outputs an alarm event that indicates that the threshold is exceeded and provides the device, value, and timestamp values. This job uses the following query definition to identify telemetry messages that should trigger an alarm:

WITH AlarmsData AS 
(
SELECT
     Stream.IoTHub.ConnectionDeviceId AS DeviceId,
     'Temperature' as ReadingType,
     Stream.Temperature as Reading,
     Ref.Temperature as Threshold,
     Ref.TemperatureRuleOutput as RuleOutput,
     Stream.EventEnqueuedUtcTime AS [Time]
FROM IoTTelemetryStream Stream
JOIN DeviceRulesBlob Ref ON Stream.IoTHub.ConnectionDeviceId = Ref.DeviceID
WHERE
     Ref.Temperature IS NOT null AND Stream.Temperature > Ref.Temperature

UNION ALL

SELECT
     Stream.IoTHub.ConnectionDeviceId AS DeviceId,
     'Humidity' as ReadingType,
     Stream.Humidity as Reading,
     Ref.Humidity as Threshold,
     Ref.HumidityRuleOutput as RuleOutput,
     Stream.EventEnqueuedUtcTime AS [Time]
FROM IoTTelemetryStream Stream
JOIN DeviceRulesBlob Ref ON Stream.IoTHub.ConnectionDeviceId = Ref.DeviceID
WHERE
     Ref.Humidity IS NOT null AND Stream.Humidity > Ref.Humidity
)

SELECT *
INTO DeviceRulesMonitoring
FROM AlarmsData

SELECT *
INTO DeviceRulesHub
FROM AlarmsData

The job sends its output to an Event Hub for further processing and saves details of each alert to blob storage from where the solution dashboard can read the alert information.

Job 3: Telemetry operates on the incoming device telemetry stream in two ways. The first sends all telemetry messages from the devices to persistent blob storage for long-term storage. The second computes average, minimum, and maximum humidity values over a five-minute sliding window and sends this data to blob storage. The solution dashboard reads the telemetry data from blob storage to populate the charts. This job uses the following query definition:

WITH 
    [StreamData]
AS (
    SELECT
        *
    FROM [IoTHubStream]
    WHERE
        [ObjectType] IS NULL -- Filter out device info and command responses
) 

SELECT
    IoTHub.ConnectionDeviceId AS DeviceId,
    Temperature,
    Humidity,
    ExternalTemperature,
    EventProcessedUtcTime,
    PartitionId,
    EventEnqueuedUtcTime,
    * 
INTO
    [Telemetry]
FROM
    [StreamData]

SELECT
    IoTHub.ConnectionDeviceId AS DeviceId,
    AVG (Humidity) AS [AverageHumidity],
    MIN(Humidity) AS [MinimumHumidity],
    MAX(Humidity) AS [MaxHumidity],
    5.0 AS TimeframeMinutes 
INTO
    [TelemetrySummary]
FROM [StreamData]
WHERE
    [Humidity] IS NOT NULL
GROUP BY
    IoTHub.ConnectionDeviceId,
    SlidingWindow (mi, 5)

Event Hubs

The device info and rules ASA jobs output their data to Event Hubs to reliably forward on to the Event Processor running in the WebJob.

Azure storage

The solution uses Azure blob storage to persist all the raw and summarized telemetry data from the devices in the solution. The dashboard reads the telemetry data from blob storage to populate the charts. To display alerts, the dashboard reads the data from blob storage that records when telemetry values exceeded the configured threshold values. The solution also uses blob storage to record the threshold values you set in the dashboard.

WebJobs

In addition to hosting the device simulators, the WebJobs in the solution also host the Event Processor running in an Azure WebJob that handles device information messages and command responses. It uses:

  • Device information messages to update the device registry (stored in the DocumentDB database) with the current device information.
  • Command response messages to update the device command history (stored in the DocumentDB database).

DocumentDB

The solution uses a DocumentDB database to store information about the devices connected to the solution. This information includes device metadata and the history of commands sent to devices from the dashboard.

Web apps

Remote monitoring dashboard

This page in the web application uses PowerBI javascript controls (See PowerBI-visuals repo) to visualize the telemetry data from the devices. The solution uses the ASA telemetry job to write the telemetry data to blob storage.

Device administration portal

This web app enables you to:

  • Provision a new device. This action sets the unique device id and generates the authentication key. It writes information about the device to both the IoT Hub identity registry and the solution-specific DocumentDB database.
  • Manage device properties. This action includes viewing existing properties and updating with new properties.
  • Send commands to a device.
  • View the command history for a device.
  • Enable and disable devices.

Next steps

The following TechNet blog posts provide more detail about the remote monitoring preconfigured solution:

You can continue getting started with IoT Suite by reading the following articles: