The segment of fail-safe sensors includes flexibly usable protective devices such as laser scanners, light curtains, photo sensors and connecting blocks. These devices have been demonstrating their industrial suitability for many years. Now, this segment is being expanded by a new series of light curtains with additional saving potentials. Light curtains and light grids are active, opto-electronic protective devices that reliably and securely protect persons at machines with regard to finger/hand guard, access protection as well as horizontal danger zone safeguarding. To improve operating results, operators of plants are constantly on the lookout for more saving potentials with which the production can be optimized and the costs be lowered further. The increasing competition makes it essential for customer-specific machines and systems to be implemented as quickly and as economically as possible. At the same time, the safety of the user must be ensured.