Devices can raise alarms via SmartREST templates such as 301, 302, 303, 304 and 305.
Devices can also clear alarms via SmartREST via the templates such as 306 and 307.
However, there is no standard way to backpropagate the alarm status to the device, if the alarm was acknowledged or cleared via Cumulocity user interface. A special operation would be appreciated. Here you can find some suggestions:
5xx,DeviceSerial,c8y_TemperatureAlarm,ACK
5xx,DeviceSerial,c8y_TemperatureAlarm,CLEAR