RFID FAQ
WHAT IS AUTOMATIC IDENTIFICATION?
Automatic identification, or auto ID for short, is the broad term given to a host of technologies that are used to help machines identify objects. Auto identification is often coupled with automatic data capture. That is, companies want to identify items, capture information about them and somehow get the data into a computer without having employees type it in. The aim of most auto-ID systems is to increase efficiency, reduce data entry errors and free up staff to perform more value-added functions, such as providing customer service. There is a host of technologies that fall under the auto-ID umbrella e.g. bar codes and radio frequency identification (RFID).
WHAT IS RFID?
Radio frequency identification, or RFID, is a generic term for technologies that use radio waves to automatically identify people or objects. There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip that is attached to an antenna (the chip and the antenna together are called an RFID transponder or an RFID tag). The antenna enables the chip to transmit the identification information to a reader. The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it.
IS RFID BETTER THAN USING BAR CODES?
RFID is not necessarily "better" than bar codes. The two are different technologies and have different applications, which sometimes overlap. The big difference between the two is that bar codes are line-of-sight technology. That is, a scanner has to "see" the bar code to read it, which means people usually have to orient the bar code toward a scanner for it to be read. Radio frequency identification, by contrast, doesn't require line of sight. RFID tags can be read as long as they are within range of a reader. Bar codes have other shortcomings as well. If a label is ripped or soiled or has fallen off, there is no way to scan the item, and standard bar codes identify only the manufacturer and product, not the unique item. The bar code on a milk carton is the same as every other, making it impossible to identify which one might pass its expiration date first.
WILL RFID REPLACE BAR CODES?
It's very unlikely. Bar codes are inexpensive and effective for certain tasks, but RFID and bar codes will co-exist for many years.
IS RFID NEW?
RFID is a proven technology that's been around since at least the 1970s. Up to now, it's been too expensive and too limited to be practical for many commercial applications. But if tags can be made cheaply enough, they can solve many of the problems associated with bar codes. Radio waves travel through most non-metallic materials, so they can be embedded in packaging or encased in protective plastic for weatherproofing and greater durability. And tags have microchips that can store a unique serial number for every product manufactured around the world.
IF RFID HAS BEEN AROUND SO LONG AND IS SO GREAT, WHY AREN'T ALL COMPANIES USING IT?
Many companies have invested in RFID to get the advantages it offers. These investments are usually made in closed-loop systems—that is, when a company is tracking goods that never leave its own control. That's because some existing RFID systems use proprietary technology, which means that if company A puts an RFID tag on a product, it can't be read by Company B unless they both use the same RFID system from the same vendor. Another reason is the price. If a company tracks assets within its own four walls, it can reuse the tags over and over again, which is cost-effective. But for a system to work in an open supply chain, it has to be cheap because the company that puts the tag on a case or pallet is unlikely to be able to reuse it.
HOW DOES AN RFID SYSTEM WORK?
An RFID system consists of a tag made up of a microchip with an antenna, and an interrogator or reader with an antenna. The reader sends out electromagnetic waves. The tag antenna is tuned to receive these waves. A passive RFID tag draws power from the field created by the reader and uses it to power the microchip's circuits. The chip then modulates the waves that the tag sends back to the reader, which converts the new waves into digital data.
WHAT IS THE DIFFERENCE BETWEEN LOW-, HIGH-, AND ULTRA-HIGH FREQUENCIES?
Just as your radio tunes in to different frequencies to hear different channels, RFID tags and readers have to be tuned to the same frequency to communicate. RFID systems use many different frequencies, but generally the most common are low-frequency (around 125 KHz), high-frequency (13.56 MHz) and ultra-high-frequency or UHF (860-960 MHz). Microwave (2.45 GHz) is also used in some applications. Radio waves behave differently at different frequencies, so you have to choose the right frequency for the right application.