[en] A method for distinguishing charge binary reactions from reactions that are not binary in charge is discussed. The method consists of measuring in coincidence with a projectile-like fragments (PLF) the characteristic K X rays of the target-like fragments (TLF). From the reaction matrix obtained in such measurements information concerning the excitation energy of the primary PLF can be extracted. This information is crucial for the understanding of the dynamics of heavy-ion reactions. The excitation energy sharing between PLF and TLF provides a test for discriminating between the abundant phenomenological models trying to describe these reactions. 1 tab., 17 figs., 20 refs