Device Vitals

Device Vitals are indicators that impact the overall health of a device. This is useful when troubleshooting connectivity issues for specific devices deployed in the field.

Particle Diagnostics -- Device Vitals

Device vitals are:

  • Collected by every Particle device: The device records information relevant to its ability to successfully connect and communicate with the Device Cloud. Cellular networking vitals are now available.
  • Sent to the Device Cloud: Vitals are automatically shared with the Device Cloud when starting a new secure session, and can be sent on a cadence using Particle.publishVitals().
  • Accessible via the Console or API: The Console exposes a Vitals Dashboard as well as the last recorded vitals. This information can also be queried via Particle's Device Cloud API.

Device Vitals can be used in-tandem with Fleet Health metrics for a bird's eye view of your IoT system's health.

You can see a device's vitals in the Console. From the devices view, click on a device from your device list.

Vitals Dashboard

Starting with Device OS version 0.8.0, each device will automatically collect health vitals and send them to the Device Cloud. Device OS version 1.2.1 also includes additional cellular networking vitals.

The device collects a variety of metrics that probe different areas that could impact successful device communications. The Vitals Dashboard takes some of the most important health metrics relayed by the device and graphs them for quick diagnosis capabilities. The Vitals Dashboard visualizes the following metrics:

  • Signal Strength
  • Signal Quality
  • Round-trip Time
  • Memory Usage
  • Battery Charge

When viewing a device in the Console, click on the Vitals tab to expose the Dashboard.

There are many other vitals collected by the device and sent to the Device Cloud. For a comprehensive list of which vitals are collected, check out the Device Vitals reference docs. To access to the full collection of vitals, see this section.

For information on upgrading Device OS versions for your devices to get the most out of Device Vitals, check out the Device OS guide.

Signal Strength

The strength of the device’s connection to the network (Cellular or Wi-Fi), measured in decibels of received signal power.

The strength of the signal is normalized as a percentage from 0-100 — the closer to 100, the stronger the signal. As a rule of thumb, the closer the device is to a tower or router, the better signal strength will be. The raw signal strength is visible by hovering over each vitals data point.

Signal Quality

The quality of the device’s connection to the (Cellular or Wi-Fi) network is a measure of the relative noise, or likelihood of interference of the signal.

Like signal strength, quality is also normalized as a percentage from 0-100 — the closer to 100, the higher the quality. As a rule of thumb, the fewer devices in close proximity communicating using similar radio frequencies, the better signal quality will be. Raw signal quality is available on the tooltip displayed when hovering over a vitals data point.

Round-trip Time

The amount of time it takes for the device to successfully respond to a CoAP message sent by the Particle Device Cloud.

A longer the round-trip time often correlates with poor signal strength or quality. Round trip time is displayed in seconds — the lower the reported time, the better the performance.

Note that only messages sent by the Device Cloud to the device like event subscriptions, function calls and variable requests are counted in the round-trip time so if a device is only sending data to the cloud through event publishes the round-trip time won't update.

Memory Usage

The amount of memory used by the device, combining the heap and the user application’s static RAM in bytes.

If a device consumes too much of its available memory, certain unexpected failures in its firmware application can occur. Memory usage is displayed as a percentage from 0-100% — the closer to 0, the less available memory is being consumed.

Battery State of Charge

The state of charge of the device’s connected battery, represented as a percentage.

If the battery charge falls too low, the device is at risk of losing power and going offline. Battery charge is displayed as a percentage from 0-100% — the closer to 100, the more charge is available to the battery.

Data resolution

Device Vitals are bucketed into varying time intervals depending on which time range is selected in the Console:

  • Last hour — 1 minute intervals
  • Last day — 15 minute intervals
  • Last 2 days — 30 minute intervals
  • Last week — 2 hour intervals
  • Last 2 weeks — 4 hour intervals
  • Last 30 days — 8 hour intervals

To change time range, use the selector visible on the top-right section of the Vitals tab.

Last recorded vitals

When viewing a device details page, will see a section for Last Vitals in the right column. This will show you the last recorded vitals information for your device:

Each vital will be analyzed and marked as either healthy or warning depending on what values are returned by the device. Learn more about diagnostic analysis in the section on test results.

You can click on the Download History link to download a CSV file containing the full list of vitals collected by the device over the last 30 days. This CSV will contain additional advanced vitals that are not rendered in the Console UI. For a comprehensive list of available vitals, check out the reference docs.

You can also click on the Health Check link to execute a real-time diagnostics test for the device. For more info on this, check out the Health Check section.

Cellular Vitals

As of Device OS version 1.2.1, cellular devices (i.e. Boron, B SoM, Electron, etc.) will begin to collect and send new vitals specific to the status and health of the cellular connection.

These vitals will appear in the Console in the Last Vitals section of the device details view:

The cellular vitals collected by the device are as follows:

  • Carrier: The cellular network operator that the device is currently using to get a connection to the Internet.
  • Radio Access Technology (RAT): The cellular connection method being used by the device (i.e. "LTE", or "3G").
  • Cell Global Identity (CGI): The unique identifier for the specific cell tower the device is currently connected to, which combines MCC, MNC, LAC, and CI.

In this case, the device is connected to an AT&T cell tower with CGI 310-410-45997-201601117 using 3G. Breaking down the CGI:

  • 310 is the mobile country code, or MCC associated with the United States of America.
  • 410 is the mobile network code, or MNC, associated with AT&T in the US. The combination of MCC and MNC tell you which carrier the device is using.
  • 45997 is the location area code or LAC, which references a group of cellular towers in a geographic area.
  • 201601117 is the cellular identity, or CI, which is the specific identifier of a single cellular tower.

This data is useful to get an understanding of how a device is attempting to connect and communicate over a cellular network. For instance, perhaps cellular devices deployed in a particular geographic area have different connectivity behaviors depending on which specific cellular tower or network operator is being used.

Sending Vitals to Device Cloud

There are a few different ways that a device can be instructed to send its vitals to the Device Cloud.

  1. Starting a secure session: When a device handshakes with the Device Cloud, it will automatically collect and send its vitals recorded at startup.
  2. Particle.publishVitals(): An API in Device OS allows you to instruct a device to send its vitals in application firmware.
  3. Refreshing from the Device Cloud: Remotely trigger a device to send its vitals ad-hoc via the Console or the Device Cloud API.

The device delivers the diagnostics data to the Particle Device Cloud via the spark/device/diagnostics/update system event. The device vitals event will include a data payload of the most recent readings the device collected.

Particle.publishVitals()

Particle.publishVitals() is a method exposed by Device OS as of version 1.2.1. It allows you to collect and send device vitals on a regular cadence as part of application firmware.

This is especially useful if you use the Device Vitals historical graphs in the Console, and want regular intervals of data for analysis. For instance, to publish vitals every hour, add the following to your setup() function:

setup () {
  Particle.publishVitals(3600);
}

loop () {
  // Your loop logic goes here
}

publishVitals() accepts one optional argument, which is the period (in seconds) at which vitals are to be sent to the cloud. If you don't pass an argument, vitals will be published once, immediately.

For the full reference docs on Particle.publishVitals(), click here.

Note: You should take care when determining how often devices should send their vitals to the Device Cloud. There's a trade off to be made: The more frequent you send the vitals, the higher fidelity of data available to you when troubleshooting. But, this comes with an increase in cellular data usage (Each vitals message is ~150 bytes). You can find the proper balance for your specific needs.

Refreshing from Device Cloud

You can instruct a device to re-send its vitals remotely via the Device Cloud.

Refresh from the Console

You can use the Console to update vitals for your device at any time:

Clicking on the refresh icon above the last recorded vitals reading will instruct the device to re-send its device vitals to the Device Cloud. If your device is online and responsive, device vitals will be refreshed.

Clicking on the Run diagnostics link will trigger running the health check, which includes refreshing device vitals.

Refresh using the API

If you'd like to programmatically instruct the device to re-send its device vitals, you can use the Device Cloud REST API. This is especially useful if you'd like to automate devices in your fleet reporting diagnostic information on a regular cadence.

You will need to make a POST request to the refresh device vitals API endpoint, then listen for the published event from the device either using the server-sent event stream or by setting up a webhook that triggers off of the spark/device/diagnostics/update event.

Health Check

In addition to device vitals, there is also the option to run a health check. Think of this as a way to run a real-time diagnostics test of the device. Note that the relevant connectivity layers vary based on the type of device (i.e. Wi-Fi vs. Cellular).

For your device, these connectivity layers can be:

For Cellular:

Device Vitals, SIM Card, Cellular Network, and
  Particle Device Cloud

For Wi-Fi:

Device Vitals and
  Device Particle Device Cloud

Device Vitals

The device itself must be in a healthy state in order to successfully communicate with the cloud. A variety of factors influence its state, such as battery state of charge, signal strength, available memory, and application firmware that does not exceed enforced rate limits.

As part of the full health check, the device will be asked to re-send its vitals to the Device Cloud. Each vital will be inspected and analyzed to ensure that it falls within a healthy range. See the section on device vitals for detailed information on what data gets sent from the device.

SIM Card

Cellular devices rely on a SIM card to facilitate a connection to the cellular network. The SIM must be in an active state, allowing the device to try to initiate a data session with the network. This test verifies the state of the SIM and reports back on whether it is currently active or not.

Note that the SIM layer will only be displayed if your Particle account has the proper access to the Particle SIM Card inside the device. For instance, if you are viewing vitals for a device claimed to your developer account, but that device is using a SIM associated with a product (not owned by your individual Particle account), the SIM Card layer will not be displayed.

Cellular Network

In addition to the need for an active SIM, the device still must be in range of a cell tower to create a healthy connection to the cellular network. Particle works with a global network of cellular carriers to allow devices to connect virtually anywhere in the world.

Particle is a mobile virtual network operator (MVNO) that enables Particle SIM cards to connect to cell towers from a variety of carriers around the world. This test verifies that the active SIM card in the device has a healthy data session with a cell tower.

Similar to what was said in the above section, you must have proper access to the Particle SIM Card being used in the device for the Cellular Network layer to be displayed in the Console.

Particle Device Cloud

The health of the Particle Device Cloud is critical to devices having the ability to successfully connect and communicate.

When running the test suite, the Particle Device Cloud services most relevant to device connectivity are automatically checked to ensure they are fully operational. Any open incident involving the services above will be reflected in the test results.

Device Service

The Device Service brokers the connection between an IoT device and the Particle Device Cloud. In addition, the Device Service is responsible for shuttling of messages to and from a Particle device.

API

The API provides a REST interface to allow remote interactions with Particle devices and the cloud. This includes calling a function, checking a variable, or publishing an event that devices subscribe to.

Webhooks

The Webhooks service allows for device data to be sent to other apps and services. Webhooks also allows devices to ingest information from these Internet services.

Running a Health Check

To run the full test suite, you can click on the Run diagnostics link from the Device Vitals UI, or click on the Health Check when viewing a device on the Console:

Click the Run Tests button to run the test suite, if the tests have not already begun to run:

For Cellular:

For Wi-Fi:

Running the tests will kick off diagnostics for each layer of the connectivity stack. Tests will be run in parallel, and the test results will be shown once all tests are completed.

Test Results

Once all of the diagnostic tests have completed, the Console will provide test results. Each connectivity layer will marked as healthy, unhealthy, or warning depending on the result of the test.

Healthy

A healthy test result means that all tests have passed successfully. The device is operating normally. This state looks like this:

For Cellular:

For Wi-Fi:

All diagnostic tests have passed and this device is healthy! Woot!

You can see that each connectivity layer has been marked as healthy, with a green check mark. You will also notice a top-level summary that confirms that all tests have passed and diagnostic vitals are in healthy ranges.

Warning

The diagnostic tests also can be marked in the warning state. In this case, one or more of the diagnostic vitals has fallen outside of the healthy range. However, all diagnostic tests still passed. This is an indication that there may be a problem, and you should investigate it further:

For Cellular:

For Wi-Fi:

In the warning state, you will receive some helpful text to explain what is happening as well as some recommendations on how to return the device to a fully healthy state.

For cellular devices, the device's battery is running low (12%) but the device is still online and able to communicate with the Particle Device Cloud. For devices with low battery, the recommendation is simple — recharge the battery before the device turns off.

For Wi-Fi devices, the device is getting rate-limited in firmware because it is attempting to publish events too quickly. The recommendation is to rework the application firmware by reducing the frequency of event publishes to 1 per second or less.

Unhealthy

The test run will be marked as unhealthy if one or more of the Remote Diagnostic tests fail. Note that failure is defined as a state in which the device will not be able to communicate with the Particle Device Cloud:

For Cellular:

This Remote Diagnostic test reports a problem because the SIM is deactivated
causing 3 tests to fail

For Wi-Fi:

This Remote Diagnostic test reports a problem because the device is unresponsive

In this state, the test will be marked clearly as failing with a red "X" icon. In this case, we are not able to successfully communicate with the Particle device. The device layer is marked as unhealthy, and we see that the device is unresponsive.

Anytime the Health Check tests fail, there will be a course of action suggested in the test results summary. These calls-to-action are designed to help your team quickly identify a solution to the connectivity issue that has arisen.

For cellular devices, the call to actionis to reactivate the SIM.

Otherwise, visit the docs to troubleshoot device connectivity. Remote Diagnostics provides this call-to-action intelligently based on the test failures.