A Tsunami detection system is based in several devices that rely on the seabed in the deep ocean and a station for data processing in earth. The devices installed in the seabed are able to indentify if some wave is above a given height. In case some of this waves is detected, a message is sent to the earth station. Besides processing the data from the devices, the earth station also queries each of the devices every 10 minutes and waits for a response for a maximum period of 10 seconds. If the device does not acknowledges the query a "device malfunction" notification is shown. Use Erlang processes and communication between them to implement this system. it is necessary to post comments to understand the code