Abstract: A method controls a light barrier where light is emitted from an optical transmitter to an optical receiver. The method checks whether reception levels fall below a lower threshold or exceed an upper threshold to determine whether the light barrier is interrupted. The thresholds initially are adjusted based on a predetermined minimum reception level, with each threshold being a fraction of the minimum reception level. An allowable reception level range is defined between the minimum level and a predetermined saturation level. The method checks whether the current reception level is outside the allowable reception level range, and, if this is the case, calibrates a parameter for operating the optical transmitter based on the minimum reception level and/or the saturation reception level. The parameter is calibrated by calculating a gradient of one characteristic curve of the light barrier and readjusting the parameter to a target value calculated based on the gradient.

Abstract: A method controls a light barrier where light is emitted from an optical transmitter to an optical receiver. The method checks whether reception levels fall below a lower threshold or exceed an upper threshold to determine whether the light barrier is interrupted. The thresholds initially are adjusted based on a predetermined minimum reception level, with each threshold being a fraction of the minimum reception level. An allowable reception level range is defined between the minimum level and a predetermined saturation level. The method checks whether the current reception level is outside the allowable reception level range, and, if this is the case, calibrates a parameter for operating the optical transmitter based on the minimum reception level and/or the saturation reception level. The parameter is calibrated by calculating a gradient of one characteristic curve of the light barrier and readjusting the parameter to a target value calculated based on the gradient.