- Barcode Scanner Selection Criteria
- 2D BARCODES: The What, Why and How.
Barcode Scanner Selection Criteria
What Type of Bar Code Scanner Should I be Using?
We currently get several calls a week asking for recommendations for selection of the proper technology for a scanner. We hope the following comments will prove of value to you in choosing between wands, CCD's and Lasers, as you configure your applications.
- Characteristics of the label itself what is the density of the bar code (characters per inch or "X" factor), the contrast between light and dark bars, the size of the label, and the overall length of the bar code.
- The application's environment reading distance from the label, required speed of reading, and duty cycle (number of reads per minute).
Wands - These are pen-shaped devices which the user moves across the barcode, at all times maintaining direct contact with the media, and therefore are used in low-volume applications. They are exceptionally rugged and consume minimal power, which also makes them a good choice for input to portable terminals and laptops. Wands can read most every barcode, even high density ones, and are sometimes the lowest cost scanner.
CCD - These are gun-shaped scanners, all solid-state with no moving parts, originally used for near-contact reading. However, technological advances have given us CCD's that can read out to nine inches, making them a superior choice for many retail and industrial applications, due to their ruggedness and modest cost. CCD's readily handle high-volume scanning applications. Generally designed as handheld units, CCD's can also be used hands-free in a self-triggered mode by addition of a stand. Fixed-mount versions are available.
Within the past few years, CCD scanners have advanced one step further. There are now CCD linear imaging scanners, which are making a great leap forward.
Advances in CCD technology have enabled new scanners to outdistance conventional laser scanners.
The advantages of linear imaging over conventional lasers include:
- brighter aiming
- higher performance on poor quality and low contrast codes
- more durability no moving parts
- significantly lower price points for equivalent performance.
Scanners using this technology offer some of these features.
- Read codes down to 3 mil density
- Five-year warranty
- Reading out to 9"
- Operation in direct sunlight or full darkness
- 2D-PDF417 Reading
Want to know about products using this technology? Click here:
Lasers - These have been the mainstay of the high-volume scanning industry. They are good choices for scanning long bar codes and those applications requiring reading at a long distance. Laser scanners can read codes down to 3 mil bar width. Versions to read out to 30 feet are available. They are very versatile scanners. Some are omnidirectional, eliminating the need for the user to orient the bar code perpendicular to the scanning beam.
2D BARCODES: The What, Why and How.
What are 2D Barcodes Symbologies that are capable of storing more information than can normally be contained in a conventional linear barcode. These include:
DATAMATRIX a square symbology, of varying densities used extensively in part marking as a large number of characters can fit in a small space:
PDF417 can be printed at a variety of aspect ratios and densities. Used in transportation, manifests, and personal ID including state drivers licenses.
Others include AZTEC, MAXICODE, and QR Code. 2D Barcodes can serve as portable data files, enabling the user to access information such as lot processing, shipment manifest, and serial number/sku data remote from the network database.
Codes such as PDF can be read by linear scanners that can rasterize in both axis. Datamatrix is a matrix code and requires an imager reader, which algorithmically processes the image. Imager scanners are effectively digital cameras with integrated processors and therefore can also capture images such as signatures. As with linear barcode scanners, they can interface as keyboard wedges or via a serial port.