The tasks of the ship's automatic systems are: signalling, blocking control, protection, management and regulation. Automatic signaling systems inform the ship's crew about the state of the ship's facilities. Automatic control systems measure various parameters of the ship's devices and compare them with the permitted values, and give sound or light signals when the parameters deviate from the set values. Automatic blocking and protection systems prevent emergency situations from occurring. If critical values of the controlled parameters occur, the protected machines are automatically switched off. The system of alarm indicators and control elements must ensure identification of malfunctions in the engine room, and satisfactory supervision of the respective equipment. This must be ensured at the central control point or, alternatively, at auxiliary control stations. In the second case, a main alarm indicator must be provided at the central control point indicating which of the auxiliary stations the fault is displayed on.