# Alarms

> Learn how statuses, redlines, Arc, and PagerDuty work together as alarms.

![](https://synnax.nyc3.cdn.digitaloceanspaces.com/docs/console/alarms/hero/601319287f2c/window-light.webp)

An alarm tells an operator that a value is outside its limits, or that a part of the system has a problem. In Synnax, an alarm is a [status](https://docs.synnaxlabs.com/reference/alarms/statuses): a named record of a condition, with a variant such as **Error** and a message. Anything can set a status: an Arc automation, a script, a task, or a person. The Synnax Console shows each change as a notification, and a PagerDuty alert task can send it to an on-call team.

A [redline](https://docs.synnaxlabs.com/reference/alarms/redlines) is different. It colors a value on a schematic or a table when the value passes a threshold, but it does not set a status and notifies no one.

## What alarms are for

### Warn about a limit

An [Arc automation](https://docs.synnaxlabs.com/reference/alarms/arc) watches a channel and sets an **Error** status when the value stays above a limit, then a **Success** status when it comes back. The operator sees one notification for each change.

### Stop a test safely

An Arc sequence moves to an abort stage when a value passes a limit. The abort stage closes valves and sets a status that tells the operator why the test stopped.

### Report a hardware fault

Tasks and Drivers set statuses when a device disconnects or a task fails. The Console shows their warnings and errors as notifications, with no setup.

### Wake the on-call team

A [PagerDuty alert task](https://docs.synnaxlabs.com/reference/alarms/pagerduty) sends the statuses that you choose to PagerDuty. An **Error** triggers an alert, and a **Success** resolves it.

### Show limits on the operator view

A redline turns a value red on a schematic or a table, so an operator sees at a glance which value is out of limits.

## Choose a tool

| Tool                                                                      | Notifies        | Use it to                                              |
| ------------------------------------------------------------------------- | --------------- | ------------------------------------------------------ |
| [Redline](https://docs.synnaxlabs.com/reference/alarms/redlines)          | No one          | Color a value on a schematic or a table.               |
| [Arc alarm](https://docs.synnaxlabs.com/reference/alarms/arc)             | The Console     | Set a status when a condition is true, or stop a test. |
| [Status from code](https://docs.synnaxlabs.com/reference/alarms/statuses) | The Console     | Set a status from a Python or TypeScript script.       |
| [PagerDuty](https://docs.synnaxlabs.com/reference/alarms/pagerduty)       | An on-call team | Send statuses outside the Console.                     |

## Statuses

Every alarm in Synnax is a status. To create, set, find, and delete statuses, and to see how the Console shows them, go to [statuses](https://docs.synnaxlabs.com/reference/alarms/statuses).