  The visual STELLA echelle spectrograph (SES-VIS) is a new instrument for the
STELLA-II telescope at the Iza\~na observatory on Tenerife. Together with the
original SES spectrograph - which will still be used in the near IR - and a new
H&K-optimized spectrograph, which is currently in the design phase, it will
extend the capabilities of STELLA with the follow up of planetary candidates
from space missions (TESS, PLATO2). SES-VIS is optimized for precise radial
velocity determinations and long term stability. We have developed a ZEMAX
based software package to create simulated spectra, which are then extracted
using our new data reduction package developed for the PEPSI spectrograph. The
focus in this paper has been put on calibration spectra, and the full range of
available calibration sources (flat field, Th-Ar, and Fabry-Perot etalon),
which can be compared to actual commissioning data once they are available.
Furthermore we tested for the effect of changes of the environmental parameters
to the wavelength calibration precision.
