The invention is described in greater detail below based on examples of embodiment shown in the drawings, which show:
FIG. 1 a first embodiment of a module for a light grid in perspective view,
FIG. 2 a vertical partial section through two coupled modules of the first embodiment,
FIG. 3 a vertical partial section of the coupling between two modules in a second embodiment and
FIG. 4 a top view of the coupling of two modules in the second embodiment.