Based on the principle of identification via induction loop (IMU), the FRED-9100 frequency decoder system is used for data exchange between train and track, enabling:

• Uni or bi-directional transmission of vehicle data at a carrier frequency of 91 kHz or 67 kHz (bi-directional transmission)

• Simple vehicle detection at a carrier frequency of 67 kHz or 91 kHz (transmission of carrier frequency only on coupling coils or inductive loops)