Monarch Instrument 9400 Series - Manual (Page 149)

Here’s why bar code 1 is wider:
•
The 8 numbers in each example appear in groups of
four or more, and they appear in even-numbered
quantities, therefore, all 8 numbers will use code C.
•
The 6 alphabetic characters will use code B.
Look at the example again. This time, data is underlined when
the character set changes.
The bar code for data arranged like this:
Bar code 1
Data = 1234ABC5678DEF
is wider than data arranged
like this:
Bar code 2
Data = 12345678ABCDEF
This shows that bar code width varies depending on how data
is arranged. Separating numeric and alphabetic characters
reduces the number of character set changes. Fewer
character set changes reduce bar code width.
The table below shows the characters per inch for Code 128.
The table shows the values for numeric data, and for
alphanumeric data at each of the three densities available on
the printer. The characters per inch for your bar code will be
somewhere between these two values, depending on the
mixture of numeric and alphabetic characters. For a precise
calculation of the width of your bar code, refer to the
specification for the Code 128 bar code.
Co
d
e
128
In
fo
rmat
io
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Appendix A - Code 128 Information
A-3