| How
do bar codes
work? |
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| Different combinations
of
bars
and
spaces
are
used
to
encode
characters
into
bar
codes.
Differences
in
light
and
dark
and
the
width
of the
elements
are
the
variables
used
for
encoding.
The
bar
code
reader
illuminates
the
symbol
and
measures
the
amount
of
light
that
is
reflected
back.
The
reader
determines
the
pattern
of
light
and
dark
or
wide
and
narrow,
then
compares
it to
the
encoding
table
for
that
type
of bar
code
(called
a
symbology)
and
decodes
the
symbol. |
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| How
many kinds of
bar codes are
there? |
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Hundreds
of bar
code
symbologies
have
been
created,
but
less
than
two
dozen
are
widely
used.
Each
symbology
has
its
own
pattern
of
bars
and
spaces
and
its
own
rules
for
encoding
data.
There
are
two
basic
types
of bar
codes:
linear
and
two-dimensional
(2-D).
Linear
codes
encode
data
in
bars
and
spaces
in a
single
line.
The
U.P.C./EAN
symbol
is the
best-known
example
of a
linear
bar
code.
Two-dimensional
codes
encode
data
in an
additional
dimension.
The
two
principle
types
of 2-D
codes
are
stacked
and
matrix
symbologies.
Stacked
symbologies
resemble
multiple
linear
symbols
stacked
on top
of
each
other.
Matrix
symbologies
feature
blocks
or
lines
in a
grid
or
geometric
pattern.
There
are
also
hybrid
2-D
symbologies
and
other
variations.
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| How
are
symbologies
different? |
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| Symbologies
differ
primarily
by the
type
and
amount
of
data
that
they
can
hold.
Some
symbologies
offer
full
alphanumeric
encoding,
while
others
only
encode
numbers.
Symbologies
may be
fixed
or
variable
length.
However,
size
isn’t
unlimited,
because
the
symbol
must
remain
compact
enough
to be
recognized
by the
reader.
Two-dimensional
symbologies
can
hold
significantly
more
data
than
linear
codes. |
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| What
kind of bar
code should I
use? |
|
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| The
variety
of bar
code
formats
available
practically
ensures
you
can
find a
symbology
that
meets
your
needs.
The
most
important
variables
that
determine
the
optimal
symbology
are
the
amount
of
data
that
needs
to be
encoded,
the
space
available
to
print
the
bar
code
and
the
type
of
data
to
encode. |
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| How
much data can
a bar code
hold? |
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| Variable-length
symbologies
can be
used
to
encode
only a
few
characters,
if
desired,
while
2-D
codes
encode
thousands
of
characters.
The
data
capacity
of
variable-length
bar
codes
is
limited
by the
size
of the
symbol,
which
is in
turn
limited
by the
ability
of the
bar
code
reader.
For
reference,
a
standard
U.P.C./EAN
symbol
encodes
14
numeric
digits.
Many
bar
code
applications
in
warehousing,
distribution,
manufacturing,
and
inventory
control
require
a
serial
number
of
similar
length,
which
many
common
symbologies
can
easily
encode
into a
compact
symbol. |
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| How
does the bar
code reader
know which
symbol it is
reading? |
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| Readers
have a
feature
called
autodiscrimination,
which
detects
the
symbology
that
is
being
processed
and
decodes
it
accordingly.
Autodiscrimination
enables
readers
to map
the
combination
of
bars
and
spaces
to the
correct
character,
thus
preventing
reading
errors.
Bar
code
data
entry
is
extremely
accurate,
with
an
error
rate
estimated
at one
error
per
more
than 3
million
characters. |
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| Can
printers print
more than one
kind of bar
code? |
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| Thermal
bar
code
label
printers
support
multiple
symbologies.
General-purpose
laser
and
inkjet
printers
and
software
applications
may
not be
able
to
natively
print
any
bar
codes
or may
not
offer
multiple
symbologies.
Printer
specifications
list
symbologies
that
are
supported. |
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| I
need to start
printing U.P.C./EAN
symbols. What
should I do? |
|
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| U.P.C.
and
EAN
bar
codes
are
part
of the
EAN.UCC
system,
which
is
managed
by the
Uniform
Code
Council
in the
United
States
and
EAN
International
in the
rest
of the
world.
Visit
their
Web
sites
for
details
and
resources
to get
started
with
U.P.C./EAN
labeling. |
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| What
do I need to
print bar
codes? |
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| To
print
bar
code
labels,
a
label
format
must
be
created
with
software
that
supports
bar
coding.
To
print
bar
codes
on
documents
or
reports,
the
application
software
needs
to
support
bar
coding
or
additional
programming
will
be
required.
After
the
label
or
form
is
designed,
it
needs
to be
output
on a
printer
that
is
capable
of
producing
bar
codes
and
supports
the
specific
symbology
that
is
used.
Because
data
is
encoded
using
differences
between
light
and
dark
(and
narrow
and
wide)
elements—which
are
measured
in
mils,
or
thousands
of an
inch—a
good
quality
printer
is
essential
for
producing
crisp
lines
and
accurate,
readable
bar
codes.
Finally,
the
media
must
support
bar
code
print
quality
by not
bleeding,
running,
fading,
or
otherwise
defacing
the
symbol. |
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| Do
I need a
special
printer to
print bar
codes? |
|
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| Many
common
laser
and
ink
jet
printers
are
capable
of
producing
bar
codes,
but
need
to be
set up
to do
so.
They
often
do not
have
native
support
for
bar
code
symbologies
and
need
to be
upgraded
with
additional
fonts
or
programming
to
support
bar
coding.
They
also
lack
many
of the
special
features
that
provide
excellent
bar
code
print
quality. |
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| How
can I hook up
a bar code
printer to my
computer
system? |
|
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Bar
code
printers
are
available
with
many
common
interfaces
to
facilitate
simple
integration
with a
variety
of
host
computer
systems.
Ethernet,
USB,
parallel,
serial,
twinax,
and
coax
cables
are
available.
Bar
code
printers
also
offer
802.11b
and
Bluetooth
connectivity
for
wireless
integration.
Management
tools
enable
remote
monitoring,
configuration,
and
troubleshooting
for
networked
printers.
Zebra
also
offers
many
advanced
connectivity
features.
These
include
embedded
XML
processors
that
enable
printers
to
decode
and
process
incoming
XML
data
streams,
interfaces
for
direct
connectivity
to SAP
and
Oracle
enterprise
resource
planning
systems,
solutions
for
the
IBM
midrange
(AS/400
and
iSeries)
environment
and
more.
Visit
Zebra’s
Web
site
for
more
information.
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| What
does
“compliance
labeling”
mean? |
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| Many
companies
require
their
suppliers
and
other
trading
partners
to
include
a bar
code
or
radio
frequency
identification
(RFID)
label
on
shipments,
which
is
used
to
sort
incoming
materials
and
manage
inventory
to
support
the
company’s
automated
systems.
Labels
produced
to
meet
trading
partner
requirements
are
called
“compliance
labels”
because
the
shipping
organization
applies
the
label
to
comply
with a
request
or
demand.
Compliance
labels
usually
must
follow
strictly
defined
formats
for
layout,
content,
bar
code
symbology,
print
quality,
etc. |
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