RFID is a technology that wirelessly recognizes objects tagged with a microscopic microprocessor. In the memory of such an electronic chip is stored a unique number, which is uniquely assigned to the tagged item, tagged place or person.
The microscopic microprocessor with an antenna connected to it is variously called, the most common terms are: RFID tag, RFID label, chip, transponder.
RFID is also an acronym for radio frequency identification.
To read a number wirelessly from the memory of an RFID tag, you need to use a device called an RFID reader and an antenna connected to it. Such an RFID system scans the space in front of the antenna and transmits the reading information to the software in fractions of a second.
On the basis of the number read, the ID, an appropriate response is taken.
For systems based on older and more common technology (LF and HF ) designed to recognize individual RFID chip-tagged objects, it will be the opening of a gate on a ski slope or a locker at a swimming pool, the recording of working hours, the opening of a barrier in a parking lot.
For the latest UHF RFID systems that recognize hundreds of tagged objects in one second, it will be, for example, instant counting of the contents of goods on a pallet in a warehouse , or on store shelves, identification of athletes at the finish line of a race, checking the contents of a package without opening it.
Imagine that you are locked in a dark room together with many people. It is so dark that you can't see anyone. You would like to find out who is with you. You call out loudly:
— Who's here?
You are answered by many voices, unfortunately they drown each other out. Then you come up with an idea on how to control the amount of information that reaches your ears. You ask everyone to choose a number, for example, from one to ten.
You further ask for people to speak up, only those who have chosen a number one. If you hear several voices again, you ask them to choose a digit again.
As only one person chose the one - only he speaks and, for example, introduces himself. One by one you ask for "twos", "threes", etc.
In this simple way you collect information about all individuals.
Analogously, an RFID reader does this by querying RFID tags and their number. And since such querying is carried out very quickly, the reader needs single milliseconds to identify a single tag. Such communication is done in accordance with Gen2 standards, (ISO 18000-C).
An appropriate radio band has been allocated for UHF RFID communications (analogous to popular radio or TV stations). All used UHF RFID systems released for sale must comply with the standard and be certified to operate only in this radio band. In this way, any interference is avoided.