RFID: Raising the Bar CODE?
MUCH has been said about Radio Frequency Identification (RFID) eventually replacing bar code technology. Some industry pundits say it’s going to happen a few years from now. In fact, a lot of businesses want to jump into the RFID bandwagon today without even understanding if the technology can really benefit them. Others haven’t even implemented bar code technology, which has already been existent for so many years and is the nearest comparison to RFID.
At this point, one should look at RFID as any other emerging technology — one that needs to be carefully evaluated and determined if the solution will really solve business issues.
Cracking the Bar Code
A Bar code is a machine-readable coding system consisting of elements with varying widths of vertical black lines and white spaces, patterns of dots, circles, square cells, and images, that when read by a bar code scanner can be converted into information.
Bar code scanners are usually interfaced with a PC via a USB, serial or keyboard wedge connection. Currently, there are Bluetooth, cordless scanners available in the market. In the near future, WiFi and bar code scanning will merge. Of course, there are handheld devices with built-in bar code scanner, WiFi, BlueTooth and GPRS capabilities, which is in the category of mobile computers and RF terminals.
Bar code systems improve the speed and accuracy of computer data entry. Bar codes are used in any applications where data needs to be automatically identified and captured efficiently and accurately in real-time for purposes of inventory management, asset tracking, product identification, warehouse picking and packing, point-of-sale, among others. Bar codes are used in many industries such as retail, transport and logistics, manufacturing, warehouse, wholesale distribution, healthcare, and government.
Bar codes are grouped into two types of symbologies: linear and two-dimensional.
Linear Symbologies. A linear (or one-dimensional or 1D) symbology bar code is made up of one single row of various widths and lengths of predefined black bars and white spaces. Normally, these bar codes are “vertically redundant” — the same information is repeated vertically. The heights of the bars can be truncated without any loss of information. The vertical redundancy allows a symbol with printing defects to still be read. The higher the bar heights, the more probability that at least one path along the bar code will be readable.
When you shop at the grocery store, the sales counter personnel uses a bar code scanner to determine the item code and price of the product you’re buying. More often than not, that product is using a linear bar code.
Two-Dimensional Symbologies. The need for ever increasing amounts of information in smaller spaces has lead to more compact and higher density symbologies found in two-dimensional (2D) symbologies. The PDF417 bar code is a more common 2D symbology. You can find this type of bar code on your driver’s license and SSS ID. There are also bar codes that are laser engraved and branded to a part. These are called Direct Part Marking (DPM.)
RFID is an AutoID (automatic identification) method, using storage and remote retrieval of information. The most practical use of RFID is for identification of objects, processes, transactions or events using radio waves to communicate information from point to point.
The basic components of RFID are the RFID tag, RFID reader, air interface for wireless communications and software application. The RFID tag is a package that can be attached to a physical object. The package houses an antenna which sends or receives radio signals decoded by a reader. A reader will use the air interface to transmit control parameters to tags and receive their assigned information via a signal. The air interface is the communication channel between tag and reader. It is limited to a radio frequency that has a finite distance over which the RFID system works. The software application enables capture and transmission of information to the backend IT systems of the business for visibility.
Indeed, the need for tracking products, people and their location is a challenging task. Today, RFID is being used to track items through a more accurate method, minimizing human error, improved visibility of products and processes and reduction in labor costs.
The applications are usually for asset management, logistics tracking, pilferage detection, counterfeit protection, airport baggage tracking, postal tracking, and supply chain management.
Comparing Bar Code and RFID
Let’s look at several areas where we can compare both technologies.
Cost — High volume tags cost as much as 25 cents each. This is expected to be reduced with increased demand for RFID and standards acceptance. High volume bar codes are virtually free. Think about this: How much does a small toothpaste tube cost? If you implement RFID on an item level today, maybe it’s more than the cost of a tag. Furthermore, bar code technology is already a proven technology, with the cost of implementation becoming more and more affordable.
Scanning — RFID offers a wider scanning range and does not require a visual line of sight to scan a tag. This means that tags placed on a carton, packed in a box, or stored in a pallet may be read. You don’t have to open each box to be scanned. Bar codes offer only a read range of inches and requires line of sight to read a bar code. The bar code should be presented to the scanner in a particular distance. Individual reading requires each box on a pallet to be opened and the item pulled to be read by the scanner. However, although requiring “line of sight”, bar code read rates are reliable even in the most challenging environments
Reliability — RFID acceptance is still in the early adoption stages. Its initial adoption in logistics is on case & pallet marking. On the item level, bar coding is still practical.
Physical Size — RFID tags can be the size of postal stamps. The ratio between a tag’s dimension in length and width is not a significant factor for the reader. Bar codes are highly sensitive to aspect radio for readability to a bar code scanner.
Lifespan — Tags have no moving parts and can be enclosed in protective material, providing a sturdy casing. Bar codes are subject to damage with excessive handling and harsh environments.
Counterfeit — Tags are produced with a unique identity code or serial number from the manufacturer. This is embedded in the microchip, and may not be altered, making them counterfeit proof. Bar codes may be duplicated and attached to products and can be counterfeited.
There is no doubt that RFID will one day become an important technology. However, bar code will still exist and can be a complementary technology to RFID. It can be a back-up, redundant technology when there’s a problem or a glitch encountered on operating and implementing RFID.
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