In this paper we have investigated the possibility of the operation of different charges in the bunch train for the nominal design of the XFEL injector and for the case that it is extended by an additional laser system on the cathode. We have examine
d the problem of similarity of beam optical functions for different bunch charges in a train. We report also about the sensitivity of the beam optical functions on the chosen compression scenario and give an overview over the working points for the settings at the injector for single charge operation as well as combined working points for different bunch pairs.
