An interrogator (Interrog) is additionally provided with a logic circuit (ActCommProt-ImplLCI) for implementing an active communication protocol and with a receiving second antenna (AI2) provided for an active communication. Said antenna is connected through an active receiver (AMActRecI) for receiving amplitude-modulated signals to said logic circuit (ActCommProtlmplLCI). A transmitting and receiving first antenna (AT1) in each transponder (Transp) is connected through an active receiver (AM-ActRecT) for receiving amplitude-modulated signals to a logic circuit (ActCommProt-ImplLCT) for implementing the active communication protocol, an output signal of which logic circuit is conducted through an active transmitter (AMActTransmT) for transmitting amplitude-modulated signals to a transmitting second antenna (AT2) for active communication. The transponder (Transp) is provided with a power supply circuit (SupplC). The passive communication protocol is a protocol according to standard ISO 15693 and the active communication protocol is similar thereto. Checking by means of the radio frequency identification system of the invention for access control can be carried out in a way comfortable for the user also at a distance from the interrogator somewhat exceeding one meter, whereas the transponder with a battery run-down has to be brought closer to the interrogator to a short distance usual till now.