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Bar
Codes & Symbols
Linear or 1D barcodes have been in use since the 1970s and
are the most
common symbology type used for automatic identification part
tracking. Today, increasing numbers of manufacturers
are using two-dimensional (2D) symbols, such as
Data Matrix, that offer greater placement flexibility and
increased data
capacity. Many industries specify the exact symbologies
which must be used, and regulate their quality.
In
addition, many manufacturers now practice “cradleto-grave”
traceability and permanently mark parts with a machine-readable
symbol that is verified at each stage of the manufacturing
process. Machine-readable symbols generally fall
into the categories of linear barcodes, stacked symbols,
2D symbols, and
Optical Character Recognition (OCR) fonts.
Types
of Data Readers
1D
or 2D - Readers can be broken down by several
categories. In the most basic of terms, there are 1D
(one-dimensional) or 2D (two-dimensional) style
readers. Many readers can do both types of codes.
Below are only a few examples of each style of bar code.
1D
Bar Code
2D
Bar Code
Composite
Bar Code Example
Reader
or Verifier - A reader is used to collect data from the
bar code. Applications for this type of reader include
retail store checkouts and inventory control. They are also
used extensively in the manufacturing sectors.
Verifiers
on the other hand, evaluate and verify the quality of the
printed code. This is done to ensure that the bar code
will be readable and is within certain industry tolerances
as defined by the bar code's particular quality
specification standard.
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