User Information
Bar code reader
11
UPC codes
The UPC-A symbols are a subset of the EAN/JAN symbols.
There are two sides, but only one code pattern set for each side.
The symbol is equivalent to an EAN/JAN-13 symbol with the
first country-of-origin character set to 0 and the second one
replaced by a number-system character. The number-system
character depends on the kind of product and whether the
symbol is applied at the factory (pre-packaged products) or at
the store (weighed items such as meat). See
Table 4
.
The UPC-E code is called the "zero suppressed" version and is
used for small packages. It requires that the number system
character and at least four of the 10 data characters be 0 (zero).
The Bar Code Reader can process both versions.
UPC-E is not divided into halves but still uses two different code
pattern sets. One is identical to the left side UPC-A set; the
other is the reverse of the right side UPC-A set. The choice of
which to use is based on the position of the data character and
the value of the checksum.
Table 4
UPC code properties
Character set
Numerals: 0 to 9
Message length
UPC-A: 12 (1 number-system character, 10 data characters,
1checksum character)
UPC-E: 6 (6 data characters & checksum character
compressed into 6 encoded characters)
Checksum
Required