First barcoding website from Romania!
Home | About Us | Solutions | Tutorials | Barcode Education | Biometric Education | Contact Us
Barcode Education » Reading Technologies

I need to read bar codes but I'm confused about readers. There seem to be these pen type things that are relatively inexpensive, or gun scanners that cost a lot more. What are the differences and what's best for me ?

What type of bar code reader to use for a given application is dependent upon a number of considerations:

» The environment in which reading will take place.
» The nature of the host computer if applicable, e.g. desktop PC or hand held computer, and whether portable or fixed position.
» The required throughput or volume of reads required.
» The quality of the codes being read and their proximity to other codes.
» The level of training/capability of the likely users.

In selecting a scanner you will usually need to consider two main features: the nature of the interface to the host device and the physical reading technology used.

Interface types

Most types of bar code reader described below are available in variants to output the bar code data using any of the main types of output format: wand (emulation), RS232 or keyboard wedge. Note that the output format must normally be specified when the reader device is ordered and the internal reader electronics usually vary between the different output methods.

Wand (Emulation) outputs the bar code as an analogue signal which requires decoding prior to being input to the host computer system. This is the simplest type of interface and relies on the wand being attached to a device that can do the decoding. Some "non-wand" scanners can sometimes be configured to send their output in the same undecoded format - a "wand emulation" mode.

RS232 output bar code readers include decoder systems, outputting the bar code data as an RS232 signal.

Keyboard wedge output bar code readers include a decoder and connect between the keyboard and the host PC. The coded data is sent to the host as key presses (the keyboard continues to operate normally).

USB (Universal Serial Bus) is an increasingly popular way to connect a scanner to more modern PCs equipped with USB ports. USB interface scanners are usually supplied with driver software enabling the scanned data to be read in as if typed at the key-board, so in most cases a USB scanner is functionally similar to a keyboard wedge interface scanner.

Cordless or wireless operate in a similar manner to either the RS232 or keyboard wedge readers but without a cable connection. They use a short range radio to transmit the scanned code back to the host. Scanners in this category come in two general types. First are scanners that have a "send only" radio that sends the scan to the receiver. The problem with these is that if, for some reason, the radio signal does not get through (maybe the user has unknowingly moved out of range of the receiver), then the user has no way of knowing this and could be sending scans literally into thin air! The second, better quality category of wireless scanners can also receive a validation signal from the base station, so the scanner will not "beep" unless the scanned data has actually been received by the base station. This second category of devices obviously cost more than the send-only units, but experience has shown that it really is worth paying the extra for the certainty that the data has been successfully transmitted.

Reader Types

There are three general bar code reading types, however there are even variations of product type within these.

Privacy Policy | Terms of Use Copyright © Rosistem