barcodes - types, working and hardware
Post on 12-Apr-2017
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TRANSCRIPT
Introduction
Why use barcodes?
Barcode types and uses
Bar-coding terminology
Barcode scanners
Advantages
Conclusion
CONTENTS
INTRODUCTIONAs far back as the 1960s, barcodes were used in industrial work environments. Some of the early implementations of barcodes included the ability identify rail road cars.
In the early 1970s, common barcodes started appearing on grocery shelves. To automate the process of identifying grocery items, UPC barcodes were placed on products.
Today, barcodes are just about everywhere and are used for identification in almost all types of business.
What is Barcode?
A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches.
Bar code is a predefined format of dark bars and white spaces
It allows real-time data to be collected accurately and rapidly
Why use barcodes?
When barcodes are used in the business process, procedures are automated to increase productivity and reduce human error.
Whenever there is a need to accurately identify or track something, bar-coding should be used
Instead of manually typing a customer identification number into a database, if the information is contained in a barcode, a data entry operator may scan it in. This would increase automation and reduce human error.
Linear barcodes 2D barcodes
Code 128 Data Matrix
UPC PDF417
Interleaved 2 of 5 Maxicode
Barcode types and useThere are 2 types of barcodes
1. Linear barcodes and
2. 2D barcodes
The type of barcode to use for a particular situation depends upon
The use
The data encoded in barcode
How the barcode will be printed
There are several different types of barcode standards for different purposes - these are called symbologies
Choosing the best type to use
Symbology
The mapping between messages and barcodes is called a symbology.
Different type of symbologies:
Codabar: Older code often used in library systems, sometimes in blood banks
Code 11: Used primarily for labeling telecommunications equipment
UPC-A: Universal product code seen on almost all retail products in the USA and Canada
Code 128: Very capable code, excellent density, high reliability; in very wide use world-wide
BAR-The darker, non reflective element of a Barcode
BI-DIRECTIONAL SYMBOL - A Bar Code symbol format which permits reading in either direction across the bars and spaces
CHECK DIGIT - A calculated character included within the Bar Code for error detection
Bar-coding Terminology
INTER-CHARACTER GAP - The space between the bars or space
SPACE - The lighter, reflective element of a Bar Code.
START CHARACTER - A special pattern of bars and spaces used to identify the beginning of a Bar Code symbol.
STOP CHARACTER - A special pattern of bars and spaces used to identify the end of a Bar Code symbol
Barcode Scanners
These are the devices used to extract information from barcode optically
Basically there are two types of scanners
1. Contact readers and2. Non-contact readers
Contact readers Must touch or come in close proximity of
symbol
Good where the label cannot be placed in an easy-to-view position
Normally hand-held/stationary units
Common type is pen/wand reader
Non-contact readersReader need not come in contact with symbol
Scan distance may be from 6” to several feet depending upon symbol size and scanner design
Hand-held, fixed beam readers
Working of barcode scanner
Basically, there are 3 functional parts to the barcode scanner itself illumination system,
the sensor / converter, and
the decoder.
Barcode scanners begin by illuminating the code with red light. The sensor of the barcode scanner detects the reflected light from the illumination system and generates an analog signal with varying voltage that represent the intensity (or lack of intensity) of the reflection. The converter changes the analog signal to a digital signal which is fed to the decoder. The decoder interprets the digital signal, does that math required to confirm and validate that the barcode is decipherable, converts it into ASCII text, formats the text and sends it to the computer the scanner is attached to.
Sensor and Converter A photo detector senses the reflected light and generates an analog signal with varying voltage. The voltage fluctuates based on whether the sensor sees the reflected light from the white spaces because the black bars absorb the red light.
Decoder – The decoder in a barcode scanner performs a variety of functions. First, it analyses the digital signal from the sensor, and tests to see if it can be interpreted as a valid barcode. In this test, it looks for uniformity of the white space (high signal) on each side of the digital signal, and uniformity between the peaks and valleys of the digital signal itself. Then, it tests the digital signal for conformance with any and all of the barcode symbologies it's designed and set up to read.
Advantages
Fast-selling items can be identified quickly and automatically reordered.
Slow-selling items can be identified, preventing inventory build-up.
The effects of merchandising changes can be monitored, allowing fast-moving, more profitable items to occupy the best space
Historical data can be used to predict seasonal fluctuations very accurately.
Items may be repriced on the shelf to reflect both sale prices and price increases.
ConclusionBarcode technology is a very useful technology
It is very cheap
Highly useful for identifying objects
Thank you Download barcode generator program
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