At the heart of any warehouse automation system are two distinct methods of labeling or identification systems: RFID and Bar codes. A Radio Frequency Identification (RFID) tag is a microchip combined with an antenna in a compact package, structured to allow RFID tags to be attached to any object to be tracked. The tag's antenna picks up signals from an RFID reader or scanner and then returns the signal, usually with some additional data (like a unique serial number or other customized information). A barcode, on the other hand, uses variations in the vertical representation of an item's unique serial identification number.
RFID tags and barcodes both carry information about products. However, there are important differences between these two technologies:
Barcode readers require a direct line of sight to the printed barcode; RFID readers do not require a direct line of sight to either active RFID tags or passive RFID tags.
RFID tags can be read at much greater distances, pulling information from a tag at distances up to 300 feet. The range to read a barcode is much less, typically no more than fifteen feet.
RFID readers can read RFID tags much faster; read rates of forty or more tags per second are possible. Reading barcodes is time-consuming, due to several factors: a direct line of sight is required, items should be properly oriented to the reader, and, reading must be done sequentially. Barcode readers usually take a half-second or more to complete a read.
Line of sight requirements also limit the ruggedness, as well as reusability, of barcodes since the printed barcode must be exposed on the outside of the product, where it is subject to greater wear and tear. RFID tags are typically more rugged, since the electronic components are better protected in a plastic cover. RFID tags can also be implanted within the product itself, guaranteeing greater ruggedness and reusability.
Barcodes have no read/write capability; that is, you cannot add to the information written on a printed barcode. RFID tags, however, can be read/write devices; the RFID reader can communicate with the tag, and alter as much of the information as the tag design will allow.
Both systems though have proven very useful in their intended applications. As such, warehousing operations stand to benefit more from the implementation of either or both of these methods.
