Functional monitoring system, in particular access control system, and method for functional control

摘要

The transmitting and receiving station generates a interrogation code signal which is identical for all of the transponders. All of the transponders that receive the signal answer simultaneously at the same carrier frequency. In order to avoid signal collisions, the transponders are synchronized before and/or during the transmission of the response signals. As an alternative, each transponder is assigned a dedicated subcarrier frequency in addition to the main carrier frequency, which is the same for all of the transponders.