Optoelectronic measurement technology does not have to be complicated. Consisting of a transmitter and a receiver, SCAN light curtains operate much like a light barrier. Infrared beams projected from the transmitter to the receiver produce a grid-type measurement field. The status of the individual light axes (”light path unobstructed” or ”light path interrupted”) is stored in the receiver. This data is then transmitted via serial interface and an PLC driver program directly into the working memory of the connected PLC control, where it can be further processed depending on the requirements of the application. For performing simple detection tasks, the presence of objects in the measurement field is indicated by means of a pnp output.