At the start of a method for analyzing a communications signal with a frequency-mask trigger unit and a selection unit, a mask which describes a trigger range for the frequency-mask trigger unit is defined in the frequency domain, in frequency and amplitude. Furthermore, within the selection unit, an application is allocated to the mask. The frequency-mask trigger unit then checks whether the spectrum of the communications signal violates the mask. Finally, the signal component of the communications signal which violates the mask is transferred to the application for a further evaluation by the selection unit.