5525B/31/32 Line Matrix Printer Code V Programmer's Reference Manual

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Chapter 3 Bar Codes
Control characters, identified by a “greater than” (>) symbol, introduce Special
Function Control Codes so that you can manually supply control codes to shift
between subsets as described in the “Mode Selection” section, below. The
bars and spaces vary in width from 1 through 4 modules. Each character
consists of 3 bars and 3 spaces that total 11 modules.
Readable Data
The optional readable data field provides a readable interpretation of the bar
code data. Readable data is printed below the horizontal bar code symbol,
and to the left of a vertical bar code symbol. The lower guard band is provided
when the readable data field is selected. The readable data field is available
only in the automatic mode.
Check Digit
The modulo-103 check digit is automatically calculated and inserted in the bar
code symbol. The check digit verifies accurate scanning. The start code is
included in the check digit algorithm.
Mode Selection
The Code V generates Code 128 bar codes in one of two modes: automatic
or manual.
Automatic Mode
The Code V creates the shortest possible bar code by automatically sending
the subset switch characters (characters preceded by >) to switch from
subset B into subset C whenever strings of four or more consecutive numeric
characters are provided. As long as the data includes ordinary keyboard
characters and no subset switch, the Code V switches in and out of subsets B
and C automatically before and after numeric character strings. Start codes,
stop codes, and check digits are generated automatically.
NOTE: The code >0 is not a special character; the Code V recognizes >0 as
the “greater than” character (>) on a standard ASCII chart.
Manual Mode
The manual mode is selected by inputting a subset switch character
(characters preceded by >) anywhere in the bar code data. In the manual
mode, you must insert the special codes into the bar code command to switch
to another subset. Once a special code is found in the data, all automatic
switching features are suspended, the readable data field option is cancelled,
and the Code V expects you to provide all special code switching commands.
In this mode, you must supply the start code; if no start code is provided, the
Code V inserts a subset B start code. Stop codes and check digits are
generated automatically in the manual mode. More information about manual
mode is provided in the following section.