Patent ID: 11936376
Assignee: ENDRESS+HAUSER SE+CO. KG
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A field device of automation technology, comprising:
a transparent control panel having a contact surface for actuation by a user on an outer side of a field device housing or a field device cover;
at least one optoelectronic button or control element that is arranged on an inner side of the transparent control panel, the optoelectronic button or control element including:
at least one transmitting unit arranged on the inner side of the transparent control panel facing away from the outer side, wherein the at least one transmitting unit is designed to transmit an optical signal in a direction of the control panel; and
at least one receiving unit corresponding to the at least one transmitting unit, wherein the at least one receiving unit is configured to receive the optical signal, and wherein the at least one receiving unit is arranged on the inner side of the control panel such that the optical signal scattered at the control panel by a finger or at another scattering object at least partially reaches the at least one receiving unit),
wherein the at least one optoelectronic button or control element is configured to detect the intensity of the optical signal incident on the receiving unit on the basis of the received optical signal and to provide an output signal dependent thereon;

an evaluation unit configured to:
define a first evaluation condition and a second evaluation condition which are used to detect the actuation of the at least one optical button or control element, wherein the first evaluation condition is used when it is detected that the field device is located in an interior area, and the second evaluation condition different from the first is used when it is detected that the field device is located in an exterior area; and
detect or evaluate whether an actuation of the at least one optoelectronic button or control element is present based on the first evaluation condition or on the second evaluation condition, wherein in the first evaluation condition, a value dependent on a time profile of an output signal originating from the at least one optoelectronic button or control element is set in relation to a current value of the output signal for detecting the actuation of the at least one optoelectronic button or control element, and in the second evaluation condition, a value independent of the time profile of the output signal during measuring operation of the field device is set in relation to a current value of the output signal for detecting the actuation of the at least one optoelectronic button or control element.