Light barrier e.g. for protection around machine tool, has beam axes which can be selectively masked, and indicates number of masked axes on display

摘要

The light barrier has pairs of light beam emitters and receivers forming a number of beam axes. An evaluation unit evaluates the received signals at the outputs of the receivers. A predetermined number of beam axes can be masked. In the evaluation unit, an object detection signal is generated when at least one interruption to a non-masked beam axis is registered. The number of masked beam axes is indicated on a display unit (16). The display may be a seven-segment display.