Barcodes have infiltrated every facet of our lives; you’ll find them in grocery stores, hospitals, department
stores, jails, on farms, even in your own home. They’ve become an accepted part of our everyday lives,
but what exactly are they and what do they represent?
You’re not alone in your confusion about the bars and spaces that are printed on food labels, shipping
boxes, letters, patient bracelets, etc. They all seem to look the same, but they’re not. Each industry has a
unique symbology as its standard, which we’ll explore later on. If you’re thinking about installing a
barcode data management system, there are many issues to consider in order to make the right choice
for your business challenges.
Get answers to all the questions that have puzzled you, and a better understanding of the technology, so
you can better plan for your own barcoding applications. In this guide, you’ll learn about:
• Barcode Basics
• Symbologies
• Scanners—Fixed, Key-Based Portable, and Wireless
• Compatibility With Existing Systems
• Application Software
• Industries and Applications
• Questions to Ask a Salesperson
• And Much More!
Barcoding 101 was designed to help forward-thinking professionals like you understand how the benefits
of barcode data management can improve your company’s productivity and increase its profit margin.
How does barcode work
Don’t be intimidated by barcodes. You don’t need to be a rocket scientist to understand them; they are
just a different way of encoding numbers and letters by using a combination of bars and spaces of varying
widths. Think of them as another way of writing since they replace key-data entry as a method of
gathering data. In business, the correct use of barcodes can reduce inefficiencies and improve a
company’s productivity thereby growing their bottom line.
Simply put, barcodes are a fast, easy, and accurate way of entering data.
This may come as a surprise to you! A barcode doesn’t contain descriptive data. Just as your social
security number doesn’t contain your name or address, a barcode is also a reference number that a
computer uses to look up an associated record that contains descriptive data and other important
information.
FOR EXAMPLE: a barcode found on a loaf of bread doesn’t contain the product name, type of
bread, or price; instead it contains a 12-digit product number. Now, when this number is scanned
by the cashier at the check-out, it’s transmitted to the store’s computer which finds the record
associated with that item number in its database. The matching item record contains a
description of the product, vendor name, price, quantity-on-hand, etc. The computer instantly
does a “price lookup” and displays the price on the cash register (it also subtracts the quantity
purchased from the quantity-on-hand.) This entire transaction is done instantly; think of how long
it would take the cashier to key in a 12-digit number for every item you wanted to buy!
To recap: a barcode typically has ID data encoded in it, and that data is used by a computer to
look up all specific information associated with the data.
Symbology: An easy definition
Symbology is considered a language in barcode technology. Just as you might speak French
while traveling in France, a symbology allows a scanner and a barcode to “speak” to each other.
When a barcode is scanned, it’s the symbology that enables the information to be read accurately.
And then when a barcode is printed, it’s the symbology that allows the printer to understand the
information that needs to be turned into a label.
How barcodes read
barcodes are read by sweeping a small spot of light across the printed barcode symbol. Your eyes only
see a thin red line emitted from the laser scanner. But what’s happening is that the scanner’s light source
is being absorbed by the dark bars and reflected by the light spaces. A device in the scanner takes the
reflected light and converts it into an electrical signal.
The scanner’s laser (light source) starts to read the barcode at a white space (the quiet zone) before the
first bar and continues passing by the last bar, ending in the white space which follows it. Because a
barcode cannot be read if the sweep wanders outside the symbol area, bar heights are chosen to make it
easy to keep the sweep within the barcode area. The longer the information to be coded, the longer the
barcode needed. And as the length increases, so does the height of the bars and spaces to be read.
There are three basic types of barcode scanners—fixed, portable batch, and portable wireless.
Fixed scanners (hand held or
mounted) remain attached to their host
computer or terminal, and transmit one
data item at a time as the barcode is
scanned.
Portable batch scanners are battery
operated and store data in memory for
later batch transfer to a host computer.
Wireless portable scanners also store
data in memory, however data is
transmitted to the host in real time. This
allows for instant access to all data for
management decisions.
Types of symbologies
barcodes come in many flavors. Most of us are familiar with the ones seen in grocery or retail stores, but
there are many others that are used as standards in various industries. Healthcare, manufacturing, retail,
etc. all have symbologies unique to their industry and aren’t interchangeable. Why are there so many
different types of barcodes? Simply because different symbologies evolved to solve specific problems.
Let’s take a quick look at a few of the most common symbologies*, and how, where, and why they’re
used:
UPC/EAN - This is the symbol used on items destined for the check-out line. UPC
symbols are fixed length, are mandatory in the retail and food industry, and not used
anywhere else for the most part. They were developed to meet the needs of grocery
retailing as it fits 12 digits into a reasonably compact space.
Code 39 - Developed because some industries needed to encode the alphabet as well
as numbers into a barcode, Code 39 is by far the most popular barcode symbology of
choice. It is typically the non-food standard barcode, and is used for ID, inventory, and
tracking purposes in various industries such as manufacturing. However, Code 39
produces relatively long barcodes and may not be suitable if label length is a
consideration.
Code 128 - This barcode came about when the need for a wider selection of
characters arose than Code 39 could provide. When label length is a consideration,
Code 128 is a good alternative because it’s very compact and results in a dense
symbol. This symbology is often used in the shipping industry where label size is an
issue.
Interleaved 2 of 5 - Another popular symbology in the shipping industry, Interleaved 2
of 5 is widely used by the warehousing industry, too. This is also a very compact
symbology and you’ll see them on the corrugated boxes in which things are shipped to
the grocery store.
Postnet - Unique to the United States Postal Service, this symbology encodes zip
codes for processing mail for speedy delivery.
PDF417 - Known as a 2D (two-dimensional) barcode, this is a high-density, non-linear
symbology that reminds you of a crossword puzzle. But the difference between this
and the other barcodes listed above is that PDF417 is really a portable data file (PDF)
as opposed to simply being a reference number. Some states require a 2D barcode be
printed your driver’s license. If your state has this requirement, it’s interesting to know
that there’s room enough in this barcode to encode your name, photo and summary of
your driving record, and other pertinent information. As a matter of fact, a PDF417
barcode can encode the Gettysburg Address in a space the size of a postage stamp!
Things to Know Before Investing in a
Barcoding System
Which Scanner Is Right For My Application?
With all the choices available, it’s critically important to understand your environment and application
thoroughly before making any decisions. Answer these few questions to help determine which scanner
is best for you:
• What type of environment will the scanner be used in?
• Harsh as in a factory or normal as in a store?
• Is continuous or periodic scanning needed?
• Is hands-free or a hand-held capability required?
• Will scanning be conducted close to the barcode or from a distance?
• What will the scanner connect to?
• Will the information scanned be needed in real time?
Remember, there are a variety of scanners suited for each application. Don’t purchase the first scanner
that seems right. The least expensive scanner might work well in an application where scanning is
infrequent, but it certainly wouldn’t be the answer in a harsh manufacturing environment where a
ruggedized scanner is needed. Ask questions and probe for additional answers.
Are Scanners Compatible With My Existing System?
Special software isn’t required to get information into your computer. Scanning and decoding are
handled by the barcode scanner/decoder. So, by the time the data gets to the computer, it has already
been translated. There’s nothing more for you to do. However, while your computer and computer
software may be capable of accepting barcode data, your existing software may not be able to print
barcodes. If it can’t, you’ll either have to buy preprinted labels from a service, or upgrade the software so
you can print your own barcoded shipping labels, pick tickets, badges, etc. This, of course, is more
convenient.
What Application Software Is Required?
Whether you want to use barcodes to track inventory, monitor patient care, for shipping and receiving, or
at point of sale, you are going to need application software. It’s the application software that accepts the
barcode data and controls the success of an application. Think of software as your computer’s silent
partner, organizing incoming data into information needed to manage business.
How do Scanners Work?
A basic barcode scanner consists of a scanner, a decoder, and a cable that interfaces between the
decoder to the computer or terminal. The scanner’s function is to scan the barcode symbol and provide
an electrical output to the computer that corresponds to the bars and spaces of the barcode. However,
it’s the decoder that recognizes the barcode symbology, analyzes the content of the barcode scanned,
and transmits that data to the computer in a traditional data format. A scanner can either have the
decoder built into its handle or be “un-decoded” which requires a separate box, called an interface or
wedge. Un-decoded scanners are also used when connecting to portable batch terminals as the
decoding is performed by the terminal itself.
Fixed Scanners
Keyboard Wedge Readers
A keyboard wedge reader is attached to a computer through a port called the keyboard interface. When
a barcode is scanned, the information is transmitted as though it were keyed in from the keyboard.
Sometimes they’re referred to as wedge readers because they physically wedge between the keyboard
and the computer and attach as a second keyboard. One great advantage of a keyboard wedge is that
barcode reading can be added with no software changes necessary; the software thinks that the data
received was entered by a speedy typist. With a wedge reader, any program that accepts keyed data
will accept barcode data with no change.
Serial barcode Scanners
Another way to transmit data from a barcode reader to a computer is to connect it to the computer’s RS-
232 serial port. The barcode information read will be transmitted in ASCII format and look just like keyed
data to the computer. Using a serial port connection is ideal for a multi-user computer. With serial ASCII
terminals for each user, the barcode reader can attach between the terminal and host computer and
transmit ASCII data just like the terminal.
Portable Batch Scanners
Portable batch scanners are hand-held battery operated readers which store data in memory for
uploading to the host at a different time. A portable batch reader contains a barcode scanner, an LCD-
display to prompt the user to perform a task, and a keyboard to enter variable data such as quantities. A
cradle must also be purchased to upload information to the computer. Portable batch scanners are ideal
when mobility is a must and when collected data isn’t immediately needed. These scanners come in a
variety of styles including hand-held, wearable and truck mounted. Your application will determine which
style is best.
Wireless Portable Scanners
When you need to collect information at a remote location, and need the information immediately, a
wireless solution is the perfect one. A wireless scanner is also built into a terminal, and uploads data to
the host as it’s scanned, instantly and accurately. Wireless products let the user scan the information at
the point of activity which makes it ideal for many industries.
Cables
The cable required depends upon how you need to connect the scanner. Cables are either RS- 232
direct cables or Synapse adapters and all require a power supply. RS-232 connections have either 9 or
25 pins and connect the scanner to the PC. A Synapse adapter enables you to use one scanner with a
variety of different PCs by simply changing the Synapse adapter cable.
Things to Know Before Investing in a
Barcoding System
Which Scanner Is Right For My Application?
With all the choices available, it’s critically important to understand your environment and application
thoroughly before making any decisions. Answer these few questions to help determine which scanner
is best for you:
• What type of environment will the scanner be used in?
• Harsh as in a factory or normal as in a store?
• Is continuous or periodic scanning needed?
• Is hands-free or a hand-held capability required?
• Will scanning be conducted close to the barcode or from a distance?
• What will the scanner connect to?
• Will the information scanned be needed in real time?
Remember, there are a variety of scanners suited for each application. Don’t purchase the first scanner
that seems right. The least expensive scanner might work well in an application where scanning is
infrequent, but it certainly wouldn’t be the answer in a harsh manufacturing environment where a
ruggedized scanner is needed. Ask questions and probe for additional answers.
Are Scanners Compatible With My Existing System?
Special software isn’t required to get information into your computer. Scanning and decoding are
handled by the barcode scanner/decoder. So, by the time the data gets to the computer, it has already
been translated. There’s nothing more for you to do. However, while your computer and computer
software may be capable of accepting barcode data, your existing software may not be able to print
barcodes. If it can’t, you’ll either have to buy preprinted labels from a service, or upgrade the software so
you can print your own barcoded shipping labels, pick tickets, badges, etc. This, of course, is more
convenient.
What Application Software Is Required?
Whether you want to use barcodes to track inventory, monitor patient care, for shipping and receiving, or
at point of sale, you are going to need application software. It’s the application software that accepts the
barcode data and controls the success of an application. Think of software as your computer’s silent
partner, organizing incoming data into information needed to manage business.
