ID Innovations Bar code Slot Reader - Visible Red and Infra Red User Manual

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Appendices

&RGH

Encodable Character Set

Entire 128 ASCII character set
Extended ASCII character set
Four non-data function characters

Data Character Density

9.1 CPI
18.2 CPI (numeric only)
(based on X = 0.010 (0.25 mm))

Non-Data Overhead

Equivalent to 3.18 alphanumeric characters

Symbol Length

Variable

Check Digit

One, Mandatory (Modulo 103)

Special Features

FNC 2 Message Append
FNC 3 Reader Initialization
FNC 4 Extended ASCII

Code 128 Characteristics

Code 128 is a bar code symbology capable of encoding the full 128 ASCII character set, the extended ASCII character set, and
four non-data function characters. It allows numeric data to be represented in a compact double-density mode, with two data digits
for every symbol character. Each character is made up of 3 bars and 3 spaces for a total width of 11 modules. Each bar or space
(element) may consist of one to four modules.

Code 128 has three different character code subsets A, B, and C. The valid characters for each of the code subsets are outlined
in the following table:

Code Subset Valid Characters

All of the standard upper case alphanumeric keyboard
characters together with the ASCII control characters
(i.e. ASCII character values 0-95) and four special
function codes ( FNC 1 - FNC 4).

All of the standard upper case alphanumeric keyboard
characters together with lower case alphabetic
characters (i.e. ASCII character values 32-127) and
four special function codes (FNC 1 - FNC 4).

Numeric data (0-9) and one special function code FNC
1.

Code 128 Subset Valid Characters

Code 128 provides four special non-data function codes, FNC 1 through FNC 4, which have been given a variety of functions to
extend the capabilities of Code 128.

FNC 1 in the first or second position following the start character identifies symbols which conform to a specific industry standard,
such as SCC-14 and SSCC-18. FNC 1 in any other position is used as a field separator.

FNC 2 (Message Append) instructs the decoder to temporarily store data from the symbol containing the FNC 2 character and
transmit it as a prefix to the next symbol data. This operation continues for all successive Code 128 symbols with FNC 2, with
messages being added to the end of the previously stored messages. When a Code 128 message is read which does not contain
FNC 2, the contents are appended to the buffer, the entire buffer is transmitted, and the buffer is cleared. This character can
occur anywhere in the symbol.

Note: Scanning a bar code that begins with a - (dash) will clear the concatenation buffer and no data will be output. In
addition, scanning a bar code of a different symbology will clear the concatenation buffer and output the new bar code.

FNC 3 (Reader Initialization) instructs the decoder to interpret the data from the symbol containing the FNC 3 character as
instructions for programming the reader. This character can occur anywhere in the symbol. The data from the symbol is not
transmitted by the decoder.

A B C D 1 2 3 4

Code 128 - 13 Mil