Standing at a grocery counter, all your groceries must definitely have gone through a barcode scanner. The counter person reads the barcode on each product with a barcode scanner after which the resulting data is sent to the computer. The computer, in turn, refers to the database for the price and description of each product.
The principle at work in barcode technology is called Symbology. It encodes alphanumeric characters and symbols, presented in black and white stripes or bars. This technology is one among the AIDC (Automatic Identification and Data Collection) technologies that work to minimize human involvement in areas such as data entry and collection, and thereby also minimize chances of errors and use of time.
The encoding aspect of this technology determines Symbology at its most basic level. It allows the scanner to know when a character starts and ends.
Structure of Barcode: Typically, a barcode comprises:
• Quiet Zone: Also known as the Clear Area, this zone comes before the Start Character of a barcode symbol. It is the least space needed for barcode scanning. It should be free of all printing and have the same color and reflect the same colors as the background of the barcode symbol. It should also be 10 times in width of the narrowest element in the specific barcode, amounting to 0.25 inch.
• Start Code: This indicates the beginning of the barcode to the scanner. It comprises special barcode characters. These characters are stripped-off and not sent to the host.
• Data: This refers to the actual data stored by the barcode.
• Check Digit: This is a mathematical sum that verifies the accuracy of all other elements of the barcode. It is identified as the extra digit at the end of the barcode which confirms that the scanner read the barcode accurately. It is stripped off from the data and not sent to the host.
• Stop Code: This indicates to the scanner where the barcode ends. They are not sent to the host but are stripped off.
• Trailing Quiet Zone: After the Stop Character, this is another clear space without any printing.
How it works: The scanning head emits LED light onto the barcode. Light is then reflected back away from the barcode into a photoelectric cell or a light-detecting electronic component. White parts of the barcode reflect the maximum light whereas black areas reflect the least.
As the scanner moves over the barcode, the photoelectric cell emits a pattern of on-off pulses corresponding to the code’s black and white stripes. The electronic circuit that forms part of the scanner converts these pulses into zeros and ones. These digits are then sent to the computer attached to the scanner which detects the code.
Applications of barcode technology: At stores, barcode technology can provide a variety of benefits, such as:
• Items that fly off the shelves are quickly identified and reordered.
• Items that are slow to sell can be identified so that they are not reordered.
• Fast-moving items can be given more space on the shelves, depending on their performance.
• Seasonal fluctuations can be predicted using historical data.
• Items can be repriced to show the earlier and new prices.
• Profiling of individual shoppers is also possible through discount cards registration.
• Barcodes are also useful in logistics and supply chain management. When a parcel is to be shipped, it is given a Unique Identifying Number (UID). The database links the UID to specific information about the parcel, such as its order number, date of packing, destination, quantity packed, etc. This information can be sent through the Electronic Data Interchange (EDI) to the retailer so that he has this information before the parcel arrives.
• Shipments sent to a Distribution Center (DC) are tracked before they can be forwarded. At its final destination, the UID is scanned so that specific store knows the contents of the parcel, its cost, etc.