Explaining RFID-101

Date: Thursday, April 28, 2016

RFID - Radio Frequency Identification

RFID is changing the way we capture data. It is a group of technologies used for data capture, using radio waves and electromagnetic fields. Data is stored on RFID tags, and read using an RFID reader and antenna.

 

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Advantages of RFID (Why use RFID)

RFID is a method of data capture but differs from other forms, such as barcodes, in that a direct line of sight is not needed in order to read data. RFID uses radio waves so a reader can listen for tags even if they can't be seen. RFID readers can also read many tags a second, capturing large amounts of data very quickly and therefore decreasing man hours and errors in warehouses and retail application. RFID facilitates a more accurate capture of data and ability to deliver information in real-time to facilitate better business decisions.

 

RFID vs. Barcodes

RFID is not a replacement for barcodes. Barcodes and barcode readers are inexpensive, and work well for capturing data. They will continue to be a popular, effective form of data capture for many years to come; however, barcodes have limitations. A barcode scanner has to have line of sight to scan a barcode; in effect is has to be able to see the barcode.There may be issues with torn or damaged barcodes which will not scan, or they are in a format the scanner cannot read. While scanning each individual barcode can go quickly, it can become time consuming to scan multiple items as well as introduce a greater margin for error. RFID's ability to read multiple tags a second without having direct line of sight, to reduce margin of error, and to capture much more data on each item, creates data capture opportunities which are not feasible using other forms of data capture.  

 
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RFID is not a single technology.  

The term RFID covers a wide range of technologies. While on the surface they appear to be similar, the underlying technology of each is different and the ability to choose the right one for each solution need is crucial to the success of that solution.  

 

  • Passive RFID - Passive RFID tags do not have their own power supply. They capture RF energy broadcast from the RFID reader's antenna, and use that energy to power up the chip. Once the tag is powered up, it instantly replies back to the reader with its data. Since the tag doesn't have its own power supply, read ranges are limited. Passive RFID tags are, however, significantly cheaper than the more powerful active RFID solutions. ScanSource currently assists with hardware needs in passive RFID solutions.

 

  • Active RFID - Active RFID tags have their own power supply, usually in the form of a battery. Since they utilize their own power, the read ranges can be much wider. They are much more expensive than passive and are used for high value or large items, such as rail cars or vehicles. Active RFID installs tend to require a great deal of customization to the given situation and solution, which add to the cost of active RFID. If you need assistance with Active RFID solutions, ScanSource can facilitate your connection to our vendor partners, as well as our solutions partners.

 

Passive RFID Technologies

There are three primary passive technologies and each operate at different frequencies, for which they are named and have their own standards to guarantee interoperability. Radio waves have different characteristics at different wave lengths giving UHF, HF, and LF different advantages and disadvantages. There is no one-size-fits-all passive technology for all applications. Most RFID hardware provided by ScanSource vendors is designed for UHF.

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UHF (Ultra High Frequency) - 860 to 960 MHz

UHF is the most popular form of passive RFID, especially in supply chain and asset tracking applications. In most instances it utilizes the cheapest tags, combined with the best performance. The price and performance of UHF are somewhat offset with difficulties working around certain materials, most notably water and metal. However, tags are available to help overcome these limitations. There is a worldwide standard for UHF RFID, ISO 18006-C, often referred to as Gen2.

 

  • Smaller tag sizes
  • Typically less expensive tags
  • Read ranges from inches out to 30+ feet (depending on tag and reader)
  • Worldwide standard ISO 18006-C/GS1 EPC Gen2
  • Specific frequency varies by region. Most common is 902-928 MHz (915MHz) in North America. 865.6-867.6 MHZ (866 MHz) in Europe.

HF (High Frequency) - 13.56 MHz

While not popular in supply chain applications, HF is used quite heavily in certain circumstances, most notably contactless payments, proximity cards, and EAS (Electronic Article Surveillance). HF read ranges are typically measured in inches, though with the right antennas the range can be extended upwards of 3 feet (1 meter). HF tends to work better around water and metal than UHF, but is usually chosen for applications where its short read ranges are actually an advantage. No one wants a contactless credit card or door access badge read from across the room. Many HF solutions are built around proprietary technology, but there is a worldwide standard for HF RFID, ISO 15693. It is also the core technology for NFC (Near Field Communication). 

 

  • Short range  
  • Works well around a range of materials
  • Tags are more expensive than UHF
  • Worldwide standard ISO 15693
  • Core technology behind NFC (Near Field Communication)

LF (Low Frequency) - 30 to 300 KHz

LF is another short range technology. It is widely used for pharmaceuticals, access control, and livestock tracking. It works well around water and even metal, but its limited read ranges and slow data speeds mean its adoption has not grown beyond niche applications. Typically LF operates at 125 KHz.

 

  • Door access, animal tracking, pharmaceuticals
  • Around 125 KH
  • Very short range
  • Works well around a wide range of materials