---
title: HMCharacteristicValueSecuritySystemAlarmType.unknown
framework: homekit
role: symbol
role_heading: Case
path: homekit/hmcharacteristicvaluesecuritysystemalarmtype/unknown
---

# HMCharacteristicValueSecuritySystemAlarmType.unknown

An alarm has been triggered with an unknown cause.

## Declaration

```swift
case unknown
```

## See Also

### Alarm Types

- [HMCharacteristicValueSecuritySystemAlarmType.noAlarm](homekit/hmcharacteristicvaluesecuritysystemalarmtype/noalarm.md)