RFID Identification Systems
RFID means radio frequency identification and refers to the use of small electronic devices consisting on a small electric circuit and antenna, with their relevant reader or scanner. The electronic circuit hosts a small microcontroller linked to a receiver RF circuit, a modulator and, in some types of RFID devices, a small EEPROM memory up to 2KB. Inside the microcontroller the identifier number for each transponder is engraved with a laser.
An important advantage of RFID devices is that they must not be positioned to be read on a precise way, avoiding then the way of reading a credit card.
The main areas, where RFID is applied, are:
- Security: control access
- Dissuasion: TAGs inside valuable objects
- Inventory: business and department stores
- Payment methods: motorways
- Purse cards: prepaid cards (Smartcard)
- Military applications: traceability applications using UHF TAGs for military containers are used on humanitarian aid, secret missions, etc.
- Goods traceability: an example could be the tracking of containers used on trains, by means of semi passive TAGs, which permit to identify the type of container and load transported, being the possible to do transport statistics on an easy way.
- Living being traceability: tracking open prison prisoners, or patients suffering illnesses who required an individualized tracking.
- USW container bins traceability: when you install a transponder on all container bins of waste collection route on a municipality, and you give them different data (collected weight, status of container bin, etc.) you have a valuable tool for optimizing working costs.
A radio-frequency identification system has three parts:
- An antenna
- A reader with hardware and software for reading data
- A programmed transponder with the necessary information
Antenna emits radio signals on a very restrictive frequency range; those radio signals have two purposes: they provide communication means between TAG and reader and, at the same time, (on passive TAGs) they provide the necessary energy for the integrated microcircuit on TAG to work. This is one of these technologies key points, RFID devices do not need to contain battery and can be operative for a long time (even decades).
Passive TAGs
They do not need battery, take energy from the very same field generated by the antenna, so they can be very small and their working life can be very long. On the contrary, their operational range is reduced because they need to use the antenna electromagnetic field to codify information to be sent back to the reader.
Active TAGs
This type of Transponder has its own source of energy, normally batteries, which allow it to communicate in an independent way without being supplied by an electromagnetic field, being its range higher than in the passive ones. On the contrary, its size is defined by batteries’ size.
Some models can act as radio beacons, emitting through regular intervals in order to save energy. As it depends on local energy supplying, its working life is about 5-10 years, always taking working ambient conditions and external temperature into account because both can affect batteries behaviour.
Summing up, RFID technologies compare to AIDC technologies (Automatic Identification and Data Collection) are better in many aspects: dust-resistance, humidity-resistance, dirt-resistance, vibrations-resistance and many other extreme working conditions. And last but not least, no line of vision and physical contact are required for the reading. Thanks to this technology you will be able to identify all kind of objects without a direct visual contact between reader and device, and most important, without human intervention for reading.