Integrated interfaces enable the quick and easy integration of these measuring light curtains into fieldbus environments without additional gateway boxes and corresponding space requirements and mounting effort. Cascade mounting with a dead zone of just 23 mm between beams, fast response times and the detection of transparent media enable e.g. gapless object tracing on a transport system. Available in this series are variants that are certified for use in potentially explosive areas of group II, category 3, zone 2 (gas) and zone 22 (dust).