---
title: "How to get notified when a datasource becomes inactive"
slug: "how-to-get-notified-when-a-datasource-becomes-inactive"
updated: 2026-03-05T13:34:25Z
published: 2026-03-05T13:38:31Z
canonical: "docs.calculus.group/how-to-get-notified-when-a-datasource-becomes-inactive"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.calculus.group/llms.txt
> Use this file to discover all available pages before exploring further.

# How to get notified when a datasource becomes inactive

## How do I know when a machine or gateway stops sending data?

A machine that suddenly stops sending data creates uncertainty. At first glance, everything may seem fine. But once updates stop coming in, you lose visibility.

- No new measurements.
- No recent activity.
- No confirmation that the machine is still operating as expected.

That is when the real questions arise:

- Is the gateway powered down?
- Is there a network interruption?
- Has the device been disconnected or damaged?
- Or is the machine simply inactive?

Without a notification, you may only discover the issue when someone happens to check the dashboard. Instead of relying on manual checks, you can configure the portal to notify you automatically when a machine or gateway stops sending data. This allows you to respond quickly and avoid gaps in your monitoring.

> [!TIP]
> Notification flow
> 
> Notifications are built from four components that work together:
> 
> - **Event definition**: determines when something becomes a warning, error, or critical event
> - **Notification preset**: determines how you are informed (portal, email, SMS, etc.)
> - **Notification role**: groups notification presets for specific users or teams
> - **Subscription**: links users to specific assets using a notification role
> 
> If you are unfamiliar with these concepts, see [How notifications are configured in the portal](/v1/docs/receiving-notifications).

## 1. How offline detection works

Offline detection is handled through an automatic event called **Data source activity**. This event is available for every datasource in the system. You do not need to create it yourself.

The system monitors whether a datasource continues to send data. If no new data is received within the expected timeframe, the event changes status. In most cases, activating the **Warning** level is sufficient to receive a notification when a datasource becomes inactive. No additional thresholds are required.

## 2. How you are notified

There is a difference between:

- When a datasource becomes inactive
- How you are informed about it

The first part is controlled by the Data source activity event. The second part is controlled by a Notification Preset.

If a suitable preset already exists, you can simply use it. There is no need to create a new one.

> [!TIP]
> Which datasource event to choose
> 
> When setting up notifications, it is important to select the datasource you want to monitor. In most situations, this will be the gateway (for example C04, C06, C07 or CX).

> [!WARNING]
> Subscribing to multiple datasources
> 
> If a machine uses multiple datasources and more than one is selected, you will receive a separate notification for each datasource that stops sending data.
> 
> This is expected behaviour and helps you identify exactly where communication has stopped.

## 3. Link the preset to a notification role

A notification preset by itself does not send anything. Think of it like this:

- The preset defines **how** notifications are sent.
- The notification role defines **who** should receive them.

The preset must be linked to a notification role, otherwise no one will be informed, even if a datasource becomes inactive. If a suitable notification role already exists, you only need to make sure the correct preset is linked to it. If no role exists yet, you can create one and connect it to the appropriate preset.

## 4. Subscribe users to machines

Even if everything else is configured correctly, notifications will only be sent when users are subscribed to specific machines. A subscription connects:

- The user
- The machine (asset)
- The notification role

If a user is not subscribed to a machine, they will not receive notifications for that machine, regardless of how well everything else is set up. It’s always worth double-checking subscriptions if notifications are not coming through.

## How data source notifications work – Overview

Offline notifications consist of four building blocks:

1. **Data source activity**: Determines when a data source goes inactive.
2. **Notification preset**: Determines how you are informed (portal, email, etc.).
3. **Notification role**: Bundles notification presets.
4. **Subscription**: Links specific users to specific machines with a specific role.

If one of these elements is missing, notifications will not be delivered.