Method for identifying a passive RFID card

A method for identifying an RFID card as a passive RFID card or an active RFID card, the method comprising the steps of:

• sending a first RFID command, while keeping an RFID field on;
• receiving, from each of at least zero passive RFID cards and at least zero active RFID cards, a corresponding first answering signal;
• populating a first list with each corresponding first answering signal from the at least zero passive RFID cards and the at least zero active RFID cards;
• sending a second RFID command, wherein the RFID field is paused for a predefined pausing period after sending the second RFID command;
• receiving, from the at least zero active RFID cards, a corresponding second answering signal;
• populating a second list with each corresponding second answering signal from the at least zero active RFID cards;
• comparing entries of the first list with entries of the second list;
• identifying each of the at least zero passive RFID cards by having its corresponding first answering signal in the first list but not in the second list;
• wherein the predefined pausing period is a first period that is specified for unloading an energy of the passive RFID card,
• the predefined pausing period is a second period that is specified for answering to the second RFID command, and/or
• the predefined pausing period is long enough to disturb any one of RFID protocol levels, and
• wherein the first period is between 50 μs and 10 μs, and the second period is between 5 μs and 0.1 μs.