Code 39 Barcode FAQ & Tutorial by IDAutomation®

Code 39 is a common barcode type used for various labels such as name badges, inventory and industrial applications. The symbology of the Code 39 character set consists of barcode symbols representing numbers 0-9, upper-case letters A-Z, the space character and the following symbols: - . $ / + %. Lower-case characters may also be easily encoded with the extended fonts provided in the IDAutomation Code-39 Font Package.

The Code 39 barcode is the easiest of the alpha-numeric barcodes to use and is designed for character self-checking, thus eliminating the need for check character calculations. Code 39 is also known as the 3 of 9 Barcode, Code 3 of 9 and Barcode39. Several standards exist that dictate how Code 39 barcodes should be printed for certain implementations. Although a checksum character is optional, many standards require it. The checksum character is a type of MOD43 calculation provided in many of the IDAutomation font tools for the Code 39 Barcode Fonts. Enabling the check digit option in IDAutomation Barcode Components and Applications allows the component to automatically generate and include the MOD43 checksum.

The complete Code 39 barcode consists of a start character, data digits, an optional check character and a stop character.

The Code 39 asterisk character is usually used as a start/stop character, and should not be part of the data in the barcode. The asterisk may be used as the start/stop character with fonts; however, this may cause problems in some applications such as MS Word, because they may treat text surrounded with asterisks as bold text. In IDAutomation Code 39 barcode fonts, the exclamation and parentheses characters are also used as start/stop characters to avoid these problems and provide additional functionality.

Printing & Generating Code 39 Barcodes

Printing of the Code 39 barcode as a font is an easy process if checksum characters are not required for the implementation. If the checksum is needed, IDAutomation provides several Font Tools, Components and Applications for this purpose.

IDAutomation Code 39 Barcode Fonts may be created directly from the keyboard or used in a calculated field to dynamically produce multiple symbols in almost any application, including Microsoft Word, Excel, FileMaker, QuickBooks and OpenOffice. To create a 3 of 9 barcode manually that encodes the data "BAR-CODE-39", the following may be performed:
    1. Select the IDAutomation Code 39 Barcode Font from the list of installed fonts;
    2. Type the start character of "*";
    3. Enter the data to be encoded, which is "BAR-CODE-39";
    4. Type the stop character of "*"

When the IDAutomation Code 39 Barcode Font is used, the parenthesis may be used as the start and stop characters to keep the asterisks from appearing in the text interpretation. For example, (BAR-CODE-39).

Several Barcode Integration Guides are also available that suggest one or more barcode 39 printing options. These integration options should be examined to determine whether to use barcode components, applications or fonts for the printing of barcodes. A few of the Barcode Integration Guides offered include the following:

Reading Code 39 Barcodes

The most common method of reading barcodes is with a barcode scanner. Most barcode scanners recommended by IDAutomation perform keyboard emulation and receive power from the USB port, so that no external power supply is required. When a barcode is scanned using keyboard emulation, the data scanned appears at the cursor as if it had been typed in from the keyboard.

MOD43 Check Character Calculation Examples

The manual calculations described below are rarely necessary. IDAutomation provides several barcode font tools, plug-ins and source code samples that are free to use with IDAutomation fonts, which automatically format the start, stop and check characters to the barcode fonts. Additionally, the check digit option in all Components and Applications calculates and includes the checksum automatically.

Perform the following to calculate the optional modulus 43 check character manually:

For example, perform the following calculations to determine the check character using the data characters "CODE39":

Encoding ASCII Character Set in Extended Code 39:

Within the IDAutomation Code-39 Font Package, extended fonts are provided to easily encode lower-case characters in addition to upper-case letters and numbers. When these fonts are not being used, or when it is necessary to encode additional characters, shift functions may be used to extend the character set according to ISO 646. In order for Extended Code 39 to be decoded properly, the scanner must first be programmed to read it. Otherwise, the scanner will simply scan the existing data, for example "+C" instead of "c."

When extended Code 39 is enabled, functions may be directly encoded by using the format $? to specify the function where ? equals the character that represents the appropriate function in the chart below. For example, Code$I3of9$M will encode Code[TAB]3of9[RETURN].

The Extended Code 39 ASCII Character Table

The Extended Code 39 ASCII Character Table
ASCII	Code39	ASCII	Code39	ASCII	Code39	ASCII	Code39	ASCII (Functions)	Code39
A	A	a	+A	0	0	ESC (Escape)	%A	SH (Start of Heading)	$A
B	B	b	+B	1	1	FS (File Separator)	%B	SX (Start of Text)	$B
C	C	c	+C	2	2	GS (Group Separator)	%C	EX (End of Text)	$C
D	D	d	+D	3	3	RS (Record Separator)	%D	ET (End of Transmission)	$D
E	E	e	+E	4	4	US (Unit Separator)	%E	EQ (Enquiry)	$E
F	F	f	+F	5	5	;	%F	AK (Acknowledge)	$F
G	G	g	+G	6	6	<	%G	BL (Bell-Audible of Attention Signal)	$G
H	H	h	+H	7	7	=	%H	BS (Backspace)	$H
I	I	i	+I	8	8	>	%I	HT (Horizontal Tabulation)	$I
J	J	j	+J	9	9	?	%J	LF (Line Feed)	$J
K	K	k	+K	!	/A	[	%K	VT (Vertical Tabulation)	$K
L	L	l	+L	"	/B	\	%L	FF (Form Feed)	$L
M	M	m	+M	#	/C	]	%M	CR (Carriage Return)	$M
N	N	n	+N	$	/D	^	%N	SO (Shift Out)	$N
O	O	o	+O	%	/E	_	%O	SI (Shift In)	$O
P	P	p	+P	&	/F	{	%P	DL (Data Link Escape)	$P
Q	Q	q	+Q	'	/G	\|	%Q	D1 (Device Control 1-XON)	$Q
R	R	r	+R	(	/H	}	%R	D2 (Device Control 2)	$R
S	S	s	+S	)	/I	~	%S	D3 (Device Control 3-XOFF)	$S
T	T	t	+T	*	/J	DEL	%T	D4 (Device Control 4)	$T
U	U	u	+U	+	/K	NU (Null)	%U	NK (Negative Acknowledge)	$U
V	V	v	+V	,	/L	@	%V	SY (Synchronous Idle)	$V
W	W	w	+W	-	/M	`	%W	EB (End of Transmission Block)	$W
X	X	x	+X	.	/N	SP (= or ~ in the fonts)	SP	CN (Cancel)	$X
Y	Y	y	+Y	/	/O	SP (= or ~ in the fonts)	SP	EM (End of Medium)	$Y
Z	Z	z	+Z	:	/Z			SB (Substitute)	$Z
Note: A space symbol cannot usually be represented from a font with ASCII 32. To overcome this problem in the Code 39 barcode fonts, replace the symbol representing a space with the "=" character. In IDAutomation Extended Code 39 barcode fonts, the "~" (tilde) character is used for a space. New 2011 Version includes a special set of TrueType fonts to encode the space character without a substitution character.

Code 39 Barcode FAQ & Tutorial

Code 39 Barcode Symbology Overview

Printing & Generating Code 39 Barcodes

Reading Code 39 Barcodes

MOD43 Check Character Calculation Examples

Encoding ASCII Character Set in Extended Code 39: