System control unit for a volumetric alarm device

System control unit for a volumetric alarm device which consists of a pulsed laser beam generator, a deflection system, a tridimensional moving unit of the deflection system, a device for the reception of the backward laser beam, a module for calculating the time of flight (TOF) between the forward and backward time of the laser beam, where said system control unit acquires a reference matrix, controls the laser driver to generate the electrical pulse to switch on and off the laser beam, manages the driver of the device which received the backward laser beam, controls the moving unit for the laser beam deflection system, manages the time of flight calculation module and acquires data from the latter, by acquiring a current matrix, manages the user interface, correlates the reference matrix with the current matrix, correlates some parameters of the current matrix with the parameters of the reference matrix, determines the alarm parameters, verifies if the alarm parameters have exceeded a threshold of change and whether the threshold of change has been exceeded, activates an alarm indicating that the monitored volume has been violated, where the transmission and the receiving optic of the laser beam is on the same axis and where that the transmitted and the reflected beam are deflected by the same deflection system