Abstract: An anti-passback algorithm for an access control system is described. The anti-passback algorithm prevents the use of valid credentials to gain access to an access-controlled area by more than one person within a given period of time. The algorithm is capable of distinguishing between credentials intentionally presented to the access control system and credentials that are unintentionally read by the access control system. Certain variables may be set by the access control system manufacturer or a trusted individual to adapt the algorithm for applications.

Abstract: An anti-passback algorithm for an access control system is described. The anti-passback algorithm prevents the use of valid credentials to gain access to an access-controlled area by more than one person within a given period of time. The algorithm is capable of distinguishing between credentials intentionally presented to the access control system and credentials that are unintentionally read by the access control system. Certain variables may be set by the access control system manufacturer or a trusted individual to adapt the algorithm for applications.

Abstract: An embodiment of the invention relates to a system comprising an optical device (10) and an evaluation device (20) for characterizing the optical device. The optical device comprising a 90° optical hybrid unit (30) having a first and second optical input (30E1, 30E2) and at least two optical outputs (30A1-30A4) wherein optical output signals (So1-So4) leaving the optical outputs have optical phase differences between each other of 90° or multiple thereof; a first photodetector (P1) connected to a first optical output (30A1) and a second photodetector (P2) connected to a second optical output (30A2), wherein the first optical output emits a first optical output signal (So1) and the second optical output emits a second optical output signal (So2), said second optical output signal having an optical phase difference of 180° relative to the first optical output signal; and a first transimpedance amplifier (Tr1) connected to the first and second photodetectors (P1, P2).

Abstract: An embodiment of the invention relates to a system comprising an optical device (10) and an evaluation device (20) for characterizing the optical device. The optical device comprising a 90° optical hybrid unit (30) having a first and second optical input (30E1, 30E2) and at least two optical outputs (30A1-30A4) wherein optical output signals (So1-So4) leaving the optical outputs have optical phase differences between each other of 90° or multiple thereof; a first photodetector (P1) connected to a first optical output (30A1) and a second photodetector (P2) connected to a second optical output (30A2), wherein the first optical output emits a first optical output signal (So1) and the second optical output emits a second optical output signal (So2), said second optical output signal having an optical phase difference of 180° relative to the first optical output signal; and a first transimpedance amplifier (Tr1) connected to the first and second photodetectors (P1, P2).

Abstract: An optical encoder, a system and a method for outputting a signal are provided. The optical encoder and the system have a shaft extending from an interior of a housing. A circuit board having a light emitting element and a light detector is connected to the housing. The light emitting element emits an amount of light within the interior of the housing. A light pipe transmits, deflects and/or directs the amount of light from the light emitting element toward the light detector. A rotor which is connected to the shaft rotates to change the amount of light received by the light detector. The shaft is connected to a sprocket which contacts a spring to produce a sound or vibration which indicates the shaft is rotating, twisting and/or turning. The circuit board outputs a signal via a cable based on the amount of light received by the light detector. The signal corresponds to a position and/or a location of the shaft.

Abstract: An optical encoder, a system and a method for outputting a signal are provided. The optical encoder and the system have a shaft extending from an interior of a housing. A circuit board having a light emitting element and a light detector is connected to the housing. The light emitting element emits an amount of light within the interior of the housing. A light pipe transmits, deflects and/or directs the amount of light from the light emitting element toward the light detector. A rotor which is connected to the shaft rotates to change the amount of light received by the light detector. The shaft is connected to a sprocket which contacts a spring to produce a sound or vibration which indicates the shaft is rotating, twisting and/or turning. The circuit board outputs a signal via a cable based on the amount of light received by the light detector. The signal corresponds to a position and/or a location of the shaft.