If the calibration files (effective area and detector response matrix) for a specific detector are available a corresponding spectrum can be simulated by using the command SIMULATE/SPECTRUM. As an obligate input a binned pulse height channel grid (labels :L_CH and :H_CH) must be provided. This can be taken from either from a similar observed spectrum, or created in a new table or taken from a default table. Of course, if the folding option is not set a flux spectrum is simulated without any use of a specific detector.