Determining position or setting of control column corresp. to certain control order

摘要

Control measures are carried out in response to the identified alteration of the light signal, e.g. its intensity in the region of the control column (1). The light signal is reflected with a respective different degree of reflection, according to the position of the control column.The altered light signal is compared with a reference light signal, for the exact determination of the alteration. Additionally or alternatively the comparison is made for taking into consideration possible system faults.