The local alarm system is a self-contained, independent alarm system which can be used for monitoring special rooms. Particularly on ships, there is the requirement of classes that rooms such as cooling and freezing loads, difficult-to-access areas, elevators, sauna, hospital etc. have to be provided with an independent alarm system. In the event of danger, for example in case of a trapped person, this shall make it possible to set off an alarm from inside the room through a locking pushbutton. After the pushbutton has been actuated inside the room, a buzzer or lamp, which is installed outside the room, will be activated. Furthermore, through serial interface, the system sends a message to the superior alarm system. A reset button outside the room will reset the alarm again.