# Monitor Devices using Ping Test

Periodically send a downlink ping to an IoT device to confirm reachability.

## Introduction

[Soracom Flux](https://docs.soracom.io/en/services/flux) is a low-code IoT application builder designed for advanced automation.

In this guide, we use Flux to periodically monitor the status of devices that use [Soracom Air SIMs](https://docs.soracom.io/en/services/air) or [Virtual SIMs](https://docs.soracom.io/en/services/arc).

We will be creating a Flux app using the Soracom API, [Sim:sendDownlinkPing](https://docs.soracom.io/en/api#/Sim/sendDownlinkPing), to determine whether devices are functioning properly. If there is not ping response, an alert is sent to Slack.

> [!WARNING]
>
> Refer to the [Pricing & Fee Schedule](https://docs.soracom.io/en/pricing#soracom-flux) for detailed information on Soracom Flux pricing.

## Requirements

For this project, you will need the following:

- A Soracom Account
- A registered IoT SIM
- A Slack account

If you don't already have a Soracom account or a registered SIM, follow the steps in the [Quick Start guide](https://docs.soracom.io/en/guides/quick-start).

## Project Overview - Device Monitoring with Downlink Ping

This project leverages Soracom Flux to continuously monitor IoT devices using periodic ping requests. An Interval Timer channel triggers the scheduled execution of the `Sim:sendDownlinkPing` API, which sends ping requests to devices identified by their SIM IDs.

If a device fails to respond to these ping requests, indicating a potential issue or loss of connectivity, the system automatically triggers a Slack notification. This alert informs operators of the offline status, allowing them to take prompt remedial action. Overall, the solution provides an automated, low-code mechanism to ensure that your devices remain connected and operational.

## Project Steps

### Create a Flux App

A [Flux App](https://docs.soracom.io/en/services/flux) can integrate various forms of inputs and apply sophisticated business logic to achieve desired outcomes.

1. Sign in to the **[User Console](https://console.soracom.io/?coverage_type=g)**. From the **☰ Menu**, expand **Soracom Flux** and select **Flux Apps**.

2. Click **+ Create a new Flux app**.

3. Name the Flux app and provide an optional description, then click **Create**.

   The Flux app will be created and the **Studio** tab in **Soracom Flux Studio** will automatically be displayed.

#### Create a Channel

A channel is a Flux [component](https://docs.soracom.io/en/services/flux#components) that connects an event source to actions in your Flux app.

1. Open the **Studio** tab in **Soracom Flux Studio**:

   - If you have just created a Flux app, you will already be in the **Studio** tab.
   - If you are returning, follow Step 1 under [Create a Flux App](https://docs.soracom.io/en/services/flux/downlink-ping/#create-a-flux-app) to access your **Flux Apps**, then select your app to open the **Studio** tab.

2. Click **+ Create a channel**.

3. Choose **Interval Timer** as the [event source](https://docs.soracom.io/en/services/flux#event-source) and click **Next**.

4. Configure the following:

   ![Interval Timer Channel](https://docs.soracom.io/_astro/timer-channel-dialog.BTLo4URJ_hCJKS.webp)

   - **Name**: Name your channel.

   - **Description**: Optionally provide a summary of the channel.

   - **Event source config**:

     - **Enabled**: Set the channel to enabled.
     - **Schedule Expression**: Set the frequency and select a time unit.
       - Example: Every `1 Hours` an event is ingested
     - **Description**: Optionally provide a description for the **Interval Timer** setting.

5. Click **Create a new channel**.

6. After confirming that your configuration is correct, click the ✕ to return to the **Studio** tab and see the new channel.

   ![Screenshot of Flux Studio showing an Interval Timer channel](https://docs.soracom.io/_astro/studio-timer-channel.DTNOk60f_1FbbQW.webp)

#### Create a Soracom API Action to Call the Sim:sendDownlinkPing API

An [action](https://docs.soracom.io/en/services/flux/actions) is a component that can be added to a channel that can conditionally process information from an event source to execute a desired effect.

In this step, we will create a Soracom API action to call the `Sim:sendDownlinkPing` API.

1. Click on the channel created in the [previous section](https://docs.soracom.io/en/services/flux/downlink-ping/#create-a-channel) to open the configuration dialog, then select the **Actions** tab and click **+ Add Action**.

   ![Select Interval Timer Channel](https://docs.soracom.io/_astro/select-timer-channel.CZJp6CHe_MD0yu.webp)

2. In the **Create a new action** dialog, choose **Soracom API** as your action type, then click **OK**.

3. Configure the following:

   - **Name**: Enter an action name.

   - **Description**: Optionally provide a summary.

   - **Enabled**: Set the action to enabled.

   - **Condition**:

     - **Action Condition**: Define when the action should trigger.

       In this case, leave this field blank so that the action executes each time the Interval Timer calls it.

4. Configure the following in the **Config** section of the dialog:

   - **API**: Select an API from the searchable dropdown.

     For the purposes of this guide, select [sendDownlinkPing](https://docs.soracom.io/en/api#/Sim/sendDownlinkPing).

   - **URL**: The URL `/v1/sims/{sim_id}/downlink/ping` is displayed, replace the placeholder `{sim_id}` with your SIM ID (e.g., `8942310000012345678`).

   - **HTTP Body**: Enter the following in JSON.

     ```json
     {
       "numberOfPingRequests": 3,
       "timeoutSeconds": 2
     }
     ```

     The example above configures 3 ping attempts, each with a timeout of 2 seconds. Set the API values as necessary for your purposes.

   ![Screenshot of sendDownlinkPing Config section settings](https://docs.soracom.io/_astro/senddownlinkping-config.UwBWcca0_1BkEUR.webp)

5. Read the warning about API calls. If you're in agreement and ready to move on, click ☑ **I understand the above and use this action** to continue.

6. Choose **Create a new SAM User** or **Select a SAM User** for this action.

   For **Create a new SAM User**, use the automatically generated name or enter the user's name in the **SAM User Name** field. The [permissions](https://docs.soracom.io/en/services/account/users-and-roles#configuring-inline-permissions) and Trust Policy for executing the selected API are automatically set and readily usable.

   > [!WARNING]
   >
   > For **Select a SAM User**, see the [Soracom API Action](https://docs.soracom.io/en/services/flux/soracom-api#config) documentation for more information.

7. Configure the following in the **Output** section of the dialog:

   **Republish the action output to another channel**: Set to **Enabled** to republish to another channel and set the following:

   - **Destination Channel**: Select **Create a New Channel**.
   - **Channel Name**: Enter a name (e.g., `Output`).

   ![API action complete dialog](https://docs.soracom.io/_astro/api-action-output.BsfbiOeb_1lp7pk.webp)

8. Click **Create**.

   The Soracom API Action will be created and you will be returned to the **Actions** tab on the channel details screen.

   > [!WARNING]
   >
   > You can view the settings of the SAM user by clicking the Soracom API action in the **Studio** tab, then clicking the link under **SAM User**.
   >
   > ![Link to SAM User permissions](https://docs.soracom.io/_astro/sam-user-link.B9yifwRv_eh6oN.webp)

9. After confirming that your configuration is correct, click the ✕ to return to the **Studio** tab and see the new channel.

#### Create a Slack Notification Action to Send Notifications to Slack

1. Click on the output channel created in the [previous section](https://docs.soracom.io/en/services/flux/downlink-ping/#create-a-soracom-api-action-to-call-the-simsenddownlinkping-api).

   ![Select Output channel](https://docs.soracom.io/_astro/soracom-flux-downlink-ping-select-output-channel.D3YugESO_1d6HGV.webp)

2. Select the **Actions** tab and click the + **Add Action** button.

3. Select **Slack Notification** as your action type, then click **OK**.

4. Configure the Slack Notification action:

   - **Name**: Name the Slack Notification action.

   - **Description**: Optionally provide a summary.

   - **Enabled**: Set the action to enabled.

   - **Condition**:

     - **Action Condition**: Define when the action should trigger.

       Set the action to execute when the `Sim:sendDownlinkPing` API fails its attempts to ping a device.

       Enter `payload.success == false`.

       ![Slack Notification action dialog](https://docs.soracom.io/_astro/slack-notification-condition.yFveHAKG_lEuwI.webp)

5. Configure the following in the **Config** section of the dialog:

   - **URL**: Enter the incoming webhook URL associated with the Slack channel you want to notify.

     For information on setting up a URL, refer to the official [Slack Documentation](https://api.slack.com/messaging/webhooks).

   - **Payload**: Specify the message you want to receive on your Slack account.

     The data received by this channel is being referenced in the **Payload** field. In this case we are using `${payload.stat}` to reference the Soracom API action's output.

     For example:

     ```text
     There is no ping response from

     SIM ID: 8942310000012345678

     ${payload.stat}
     ```

6. Configure the following in the **Output** section of the dialog:

   - **Republish this action output to another channel**: Set republishing to **Disabled**.

7. Click **Create**.

## Testing the Flux App

### Confirm Sim:sendDownlinkPing API Execution on Target SIM

Verify that the device with the target SIM ID is able to respond when the Interval Timer event in your Flux App is triggered.

Confirm the status of your device. If the device is powered off or unable to respond to the ping at the time of execution, the `Sim:sendDownlinkPing` API call will return a status of `false`.

You can test if the setup is working by powering off the device, then running the app in order to see if you receive a Slack notification. If you receive a Slack notification, it verifies that your **Action Condition**, `payload.success == false` has been met.

### Check the Execution History of the Flux App

1. Sign in to the **[User Console](https://console.soracom.io/?coverage_type=g)**. From the **☰ Menu**, expand **Soracom Flux** and select **Flux Apps**.

2. Click on the Flux app you created.

3. Select the **History** tab.

   For each channel, the Message, Context, Input, and Output of the action executed from that channel are displayed. For more information, see Execution History.

> [!WARNING]
>
> To learn about detailed logging, see the [View Logs](https://docs.soracom.io/en/services/flux/logs) documentation.