Slits are introduced by the following assignments. They are part of /online_dir/exp_ini.exp
SLT1_BOTTOM = E2_MOT17 SLT1_TOP = E2_MOT18 SLT1_RIGHT = E2_MOT19 SLT1_LEFT = E2_MOT20 SLT2_BOTTOM = E2_MOT21 SLT2_TOP = E2_MOT22 SLT2_RIGHT = E2_MOT23 SLT2_LEFT = E2_MOT24 SLIT_NAMES = "SLT1, SLT2"
The coordinate system: z points in the direction of the photons, y points upwards, x completes the right-handed coordinate system. 'right' points in the x-direction, like in school.