A barcode is a visual identification that can be read by a machine. Barcodes come in different formats, traditionally as linear codes that consist of a series of parallel lines of varying width and spacing and 2D barcodes, which are usually a circular or rectangular matrix pattern.
Different types of barcode reader are available but the most common are laser scanners and camera-based readers. Laser scanners send a laser beam across the barcode and read the reflection. These operate up to a distance of about 1 m. Camera-based readers take a picture of the bar code and analyse it. The operating distance may depend on the size of the bar code and the quality of the camera. Many modern smartphones can read traditional barcodes using in-built cameras. Camera-based readers are normally used to read 2D barcodes.
The primary advantage of a barcode system is its price
It is relatively inexpensive to attach a barcode to a device. Compared to other technologies, it is less susceptible to errors because staff can see whether the laser scanner is reading the correct ID Tag. However, this has the disadvantage of making any automatic set-up very difficult to achieve. So usually in practice, a combination of RFID chips and bar codes are used.
- ID Tags and readers are inexpensive
- Mature technology
- No batteries required
- Requires infrastructure for readers
- Normally requires a person to operate the reader
- The barcode must be visible for the reader