1. What is RFID ?
2. How does RFID work ?
3. What is the difference between HF and UHF ?
4. What benefits does RFID have over barcodes ?
5. On what frequencies does RFID run ?
2. How does RFID work ?
3. What is the difference between HF and UHF ?
4. What benefits does RFID have over barcodes ?
5. On what frequencies does RFID run ?
RFID (Radio Frequency Identification) is an automatic identification method that stores and remotely retrieves data via an RFID tag or transponder.
An RFID programmer encodes information onto a tiny microchip within a thin RFID tag that looks much like a normal pressure-sensitive carton label. This tag is attached to a carton as it begins its supply chain journey from manufacturing plant to retailer.
RFID readers that work on the same protocol as the tags are distributed at key points throughout the supply chain. These readers activate the tag, causing it to broadcast high frequency radio waves within bandwidths reserved for RFID usage by individual governments. These radio waves transmit identifiers or codes that reference unique information about products inside the carton.
Readers relay the codes to a host computer as the carton passes through an RFID portal or moves along a conveyor anywhere in the supply chain. The computer parses this information and makes it readily available to anyone who needs to know where a product is at any given moment.
The first difference is the operating frequency. UHF (Ultra High Frequency) is 860-960MHz depending on the country of use and HF (High Frequency) works at 13.56MHz.
Generally the operating range for HF is less than 1 foot while UHF can operate at significantly longer distance.There are also differences in performance related to the types of products the inlays or labels are attached to as well as the operating environment.
RFID is a read/write technology. It can write / program the data after it is attached to the product. This offers a higher level of flexibility to track and update the data as the product goes through the supply chain, into the end use application or beyond.
1) Barcode labels must be seen to be read. RFID labels / tags do not have to be seen to be read.
2) Barcode labels may not be readable if they are incomplete or dirty. RFID labels / tags integrity are maintained as there are underneath the actual labels / tags, inserted within the packaging or incased in a durable material.
3) Barcode labels must be placed on the outside of the product / packaging. RFID labels / tags can be read even when multiple tagged products are sealed inside a carton (for example).
4) Barcode labels must be orientated on the product / packaging so the barcode is in-line with the scanner. RFID labels / tags are often orientation insensitive, meaning the tagged item not only does not have to be seen to be read, but also can be in any orientation.
5) Barcode labels provide only one ID for each package of a carton, pallet or individual package of a product. For example: a 12 ounce bottle of your favorite soda will have the same barcode on every 12 ounce bottle of that same soda. RFID labels / tags provide an unique ID for each product and can be associated with individual information such as the manufacturing location, date shipped, lot number etc.
6) Barcode labels are printed, or written once, and cannot be changed at any time throughout the supply chain without another barcode label attached over the original label. RFID labels / tags provide read/write technology. The data can be written / programmed, can be changed or updated at any time in the supply chain and even into the end use application or beyond.
Like all wireless communications devices, RFID tags and readers operate under assigned frequencies. In the United States, these frequencies are assigned by the Federal Communications Commission (FCC). The European Union’s frequency assignments are governed by the European Telecommunications Standards Institute (ETSI).
Most of the world uses frequencies defined within the ETSI or FCC designations. The FCC allows several frequency bands to be used for RFID including the 125KHz, 13.56MHz , and 902-928MHz bands. Low Frequency (LF) tags operate in the 125KHz range. Tags operating in the 13.56MHz range are referred to as high frequency (HF) tags. RFID tags operating 902-928MHz band are referred to as ultra high frequency (UHF) tags. In North and South America, for example, 902-928MHz band is commonly used for asset management. The ETSI recommended UHF RFID operational frequencies for Europe are between 865-868MHz.
While there are many differences between UHF and HF tags, the most relevant differences are the following :
- UHF tags have longer ranges and are thus more suitable for supply chain applications (i.e. reading cartons and pallets at a distance of tens of feet).
- HF and LF tags have shorter ranges and have therefore been the technology of choice for proximity applications such as library book tagging and security access control (i.e. reading at a few feet).
- Many applications like retail apparel tagging and supply chain applications are based on the 902-928MHz frequency band. Applications for payment cards and library book tagging use the 13.56MHz band.