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How Does a Barcode Work?

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POSMarket.com.au  offers their expertise in Point of Sale (POS) solutions such as barcode scanners, label printers, receipt printers, cash drawers and mobile computers.

The following article refers to the purchase of commercial barcodes. Barcodes can be printed in-house by a business for their own internal use without needing to purchase the barcodes.

How does a barcode work? How does the scanner know what price to charge? Who decides what barcodes go on what products?

The barcode is called a Universal Product Code, or UPC. The earliest use for UPC codes was to label and keep track of railroad cars, but because the labels on the cars became dirty, the scanners couldn't read them very well and the system was set aside.

Later the technology was re-visited to enable better tracking of grocery product inventory and to speed up the checkout process. They are now used in almost every major store.

The barcode is a representation of machine readable information. The first six digits are the product manufacturer's identification.

A company that wants to use barcodes has to apply for permission from the Uniform Code Council Company. They pay an annual fee for the use of the system. The company is then assigned an identification number.

The next five digits of the barcode is the assigned item number. A person at the Universal Code Council Company called the UPC Coordinator assigns numbers to items the manufacturer wants to barcode. This person also retires codes from products that are no longer sold.

Every item needs to have its own number and the UPC Coordinator has to keep them in order.

The last digit in the code is a number that lets the scanner know if the barcode has been read correctly, or if the barcode is scanned upside down.

This number is the sum of a special math equation that the scanner performs when it reads the barcode. If the equation is wrong, the product needs to be rescanned.

Sometimes on a small item, the excess zeros are left off by a special configuration to save space. These are called suppressed zeros.

There is no actual price information in the barcode. Every store that uses barcoding has a central Point of Sale or POS computer that stores the barcodes for all items in the store as well as the accompanying information and prices.

The scanner communicates with this computer to access this information. Not having the information on the actual barcode allows the store to change the price information when they need to, all in one place as opposed to changing it on every individual item.

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