Frequently Asked Questions about RFID
What exactly is an RFID Tag?RFID tags are small radio transponders that are attached to objects. RFID tags are typically made out of two parts: a chip and an antenna. The chip has different memory size from 96 bit to 8 KB or even more worth of information, such as a serial number, an ID number, date of birth, name etc. There are different types of RFID tags, active, passive and battery assited passive. Passive RFID tags are small data transponders that are powered by the radio waves received from a querying RFID reader - these tags are "woken - up" by the reader. A reader is a device that has one or more antennas that send radio waves to the tag and receive signals back from the tag. The reader then passes the information in digital form to a computer system.And Active RFID Tag has a inbuilt battery in it,the tags sends the information in pre defined time interval and gets identified by the reader when comes in its vicinity.Read range is much higher in Active RFID.
If there are different radio frequencies used with RFID tags how do you know which is best?
This is determined by the application and how you wish to gather and use the information on the RFID chip. There are a few general rules.
- UHF (860 - 950 MHz) has longer read range, generally 8 -20 feet, faster read rates and is more commonly used for inventory applications,
- HF (13.56 MHz) has a shorter read range, generally 4-25 inches, is less susceptible to disruption and is more commonly used for identification and financial transactions,
- LF (125 - 133 kHz) has the shortest read range, is least susceptible to disruption and is often used for access control and livestock identification
Is RFID a "plug and play" technology?
Absolutely not! The environment around the tag especially the material(s) in close proximity to the antenna makes a tremendous difference to the performance of the tag and the system as a whole.
Is RFID reliable? When properly deployed, YES! From Government agencies to hospitals to Wal-Mart, RFID systems have proven their ROI in mission critical track and trace applications.
Isn't an application specific design going to be expensive?
The radio link from RFID tag to RFID reader is the point of departure from your fixed network to your mobile assets. What is really expensive is the lost time and efficiency if this link is not reliable. The value of an RFID deployment is in the ability to access data about specific items easily, in real time. There is no value if the system fails because of inferior tag design and performance.
What are some of the common standards used in RFID applications?
ISO 14443: This HF standard is used for close proximity tags (typically 1- 5 cms). These tags are often used for financial transactions (credit cards, transit applications) and identification (passports). The standard allows for secure encrypted communication between the tag and reader.
ISO 15693: This HF standard is used for inventory and general purpose identification. Many library systems use this standard to take advantage of tag interoperability and intermediate read range ( 0- 1.5 meter depends upon antenna) which fits well with the operating use case of library POS,inventory,sorting and Anti Theft.
ISO 18000-(6) or EPC Class 1 Gen2: This is a worldwide UHF standard used for inventory management. Tags using this standard operate in three distinct frequency bands
- 865 - 868 MHz for communication in the European Union
- 902 - 928 MHz for communication in North and South America, as well as multiple Asian countries
- 950 - 956 MHz for communication in Japan.
While every business is different and the processes vary widely, RFID is an inventory monitoring technology. Properly deployed the technology enables real time monitoring and decision making. For example a business might use RFID tags on items in an outgoing shipment to automatically trigger an invoice as the shipment leave the dock. In another example a service technician can access the maintenance record of an RFID tagged object , in real time from the data stored in the tags memory