Barcodes: What You Scan Is What You Get

The technical foundation of barcode technology originated in the 1940s with an effort to automate the checkout process in grocery stores. Interestingly, despite the enormous worldwide success and explosive growth of barcodes everywhere, the fully automated checkout remains the holy grail of automated data collection.

As an alternative to the traditional barcode “zebra-stripes” that we are all familiar with, the past decade has seen some evolutionary growth of non-directional radio frequency identification (RFID) solutions. RFID systems require electronic tags (either passive or battery-based active devices) and radio-frequency excitation/reading portals to activate and detect the presence of RFID tags within range. RFID's ability to find and read data packets from any tagged item or asset in close proximity offers advantages in certain applications; however, technical challenges still remain.

Barcode technologies have similarly marched forward with the development of linear and 2D code formats along with versatile printing and scanning technologies. This progress has allowed barcodes to maintain their utility for automatic data collection and inventory tracking.

Barcodes offer high-speed, reliable data collection and on-the-fly processing. Barcode label printers can generate fixed or variable barcode data (e.g., multiple batch production labels or individual sequential serial number labels). Similarly, barcode readers can scan thousands of items per hour with high accuracy. This allows a supply chain to boost production and packaging rates on the front end, accelerate material handling throughout the distribution channel and record end-user transactions at the far end.

A well trained data-entry clerk will typically make a single error once every 250 to 300 keystrokes. By comparison, worst-case barcode scanning operations generate an error an average of once every 500,000 scans. The latest generation of barcode formats and scanning equipment have error rates better than 1:1,000,000, and in some applications, better than 1:10,000,000.

Types of Barcodes

From baby formula to boogie boards, barcodes have universal reach. Virtually every consumer product sold today carries a UPC (Universal Product Code), a unique identifier that specifies manufacturer and product details. Beyond the consumer market, barcodes are all around us — from hospitals to manufacturing lines, driver's licenses to shipping boxes.

The technology that began decades ago as a graphical representation of Morse Code's dots and dashes has today evolved into more than 30 linear barcodes and, more recently, more than 40 2D barcodes capable of encoding additional data.

The most common linear barcode is the UPC, while other linear codes offer additional versatility, particularly in manufacturing applications for production lot and serial number tracking (Code-39) or postal applications (POSTNET).

Multi-dimensional (2D) codes came into vogue by an effort to increase the data density of barcodes, enabling them, for example, to encode complete delivery address information on shipping cartons. Two widely recognized codes are MaxiCode, originally developed by UPS, and PDF417, developed by Symbol Technologies (now owned by Motorola).