Optoelectronic operating element i.e. optoelectronic key, for field device of process automation technique in gas atmosphere for operating devices, has evaluating unit determining whether user contacts/not contacts panel based on signals

摘要

The element has a transmitting unit (101) e.g. infrared transmitting diode, for periodically radiating a light signal (103) in a direction towards a panel (100) for detecting contact of the panel by a user. A receiving unit (102) e.g. infrared receiving diode, detects a reference signal during a reference interval of the period. The units are active during a measuring interval of the period. The receiving unit detects a measuring signal during the measuring interval. An evaluating unit determines whether a user contacts or not contacts the panel based on the signals. The panel is made of glass or plastic permeable for infrared rays. Independent claims are also included for the following: (1) a field device (2) a method for detecting actuation of an optoelectronic operating element.