I-1
Appendix I
Code 128 Specifications
Code 128 is a very powerful bar code, combining an extensive character set and
variable length with compactness and error checking. The character set contains
all 128 ASCII characters with each character made up of three bars and three
spaces. (No double characters are required to make up lower case ad special
characters). Each element (bar or space) varies from one to four units in width,
totaling 11 units of width per character. Code 128 contains two levels of error
checking:
•
Each character is checked for internal parity,
and
•
The last character is a checksum.
Code 128 has three subsets, A, B and C. Subset A contains
alphanumeric characters and unprintable control
characters, subset B contains alphanumeric characters
plus printable control characters and subset C contains
only numeric characters and uses a 2-character encoding
scheme to create a more compact bar code. Code 128 uses
an internal Mod 103 check character that is not displayed
by the bar code reader. Code 128 bar codes can be made up of only one
subset or may be a combination of several.
The Code 39 features of
Accumulate Mode
,
Caps Lock ON
and
Caps
lock OFF
also apply to Code 128.
UCC-128/ EAN-128
UCC-128/EAN-128 Code is a subset of Code 128 adopted by the UCC and
EAN council’s product, container, and shipping label symbology.
UCC/EAN-128 bar codes always start with a Function Code 1 character. In
addition, all variable length fields are terminated by a Function Code 1
character unless they are the last field in the bar code.
The TriCoder outputs the following for the special function codes and start
sequences:
]C1 Start C/Function Code 1
^] (GS) Function Code 1 as a variable string terminator
If
UCC/EAN 128
is
enabled
, the reader looks for the Function Code 1 as
the leading character, and treats all such codes as UCC/EAN 128 bar codes.
A subset of UCC/EAN-128 is the
UCC or EAN Serial Shipping
Container Code
; it’s specification calls for a 19 digit UCC/EAN 128 code
with an additional Mod 10 Check digit (20 digits in all). The Mod 10 Check
digit is calculated the same as the
Interleaved 2 of 5
example in
Appendix J
.
It is the 20 digit data length (including the MOD 10 check digit) and the
MOD 10 check calculation that distinguishes the
UCC
Serial Shipping
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