Code 39 Introduction

Code 39 is an alphanumeric bar code. It is a discrete, variable-length symbology. It is still widely used-especially in inventory and industrial applications. It is the standard bar code used by the United States Department of Defense, and is also used by the Health Industry Bar Code Council (HIBCC). It is designed to encode 26 uppercase letters, 10 digits and 8 special characters(-, ., *, $, /, +, %, SPACE). It can be extended to code all 128 ASCII characters by using a two character coding scheme. Each data character encoded in a Code 39 symbol is made up of 5 bars and 4 spaces for a total of 9 elements. Each bar or space is either “wide” or “narrow” and 3 out of the 9 elements are always wide. That’s what gave the code its other name – Code 3 of 9.

Code 39 Check Digits Calculation

Code 39 does not normally include a check character, however there is an established check character for applications that need it. The value of each data character is summed up and divided by 43. The remainder is the value of the character to use as the check character. you can find the value of each character in the following table.

To calculate the optional checksum digit example :”EASESOFT1234″.

String	E	A	S	E	S	O	F	T	1	2	3	4
Value	14	10	28	14	28	24	15	29	1	2	3	4

1. Sum the value of each of the values of each of the characters ,The sum is 14+10+28+14+28+24+15+29+1+2+3+4=172.
2. Divide 172 by 43,the remainder is 0,so the checksum digit is 0.

Code 39 Encoding Table

Code 39 starts with ‘*’ and stops with ‘*’. The table below shows the Code 39 character set.The barcode pattern means the first character is Bar,the second is Space,the Third is Bar, The “w” indicates a wide element and the “n” indicated a narrow element. Please note that every character starts and ends with a bar .We set the wide-to-narrow ratio as 3, the intercharacter gap width as 1 space.

 

 

VALUE	CHAR	PATTERN	VALUE	CHAR	PATTERN
0	0	NNNWWNWNN	22	M	WNWNNNNWN
1	1	WNNWNNNNW	23	N	NNNNWNNWW
2	2	NNWWNNNNW	24	O	WNNNWNNWN
3	3	WNWWNNNNN	25	P	NNWNWNNWN
4	4	NNNWWNNNW	26	Q	NNNNNNWWW
5	5	WNNWWNNNN	27	R	WNNNNNWWN
6	6	NNWWWNNNN	28	S	NNWNNNWWN
7	7	NNNWNNWNW	29	T	NNNNWNWWN
8	8	WNNWNNWNN	30	U	WWNNNNNNW
9	9	NNWWNNWNN	31	V	NWWNNNNNW
10	A	NNWWNNWNN	32	W	WWWNNNNNN
11	B	NNWNNWNNW	33	X	NWNNWNNNW
12	C	WNWNNWNNN	34	Y	WWNNWNNNN
13	D	NNNNWWNNW	35	Z	NWWNWNNNN
14	E	WNNNWWNNN	36	–	NWNNNNWNW
15	F	NNWNWWNNN	37	.	WWNNNNWNN
16	G	NNNNNWWNW	38	SPACE	NWWNNNWNN
17	H	WNNNNWWNN	39	$	NWNWNWNNN
18	I	NNWNNWWNN	40	/	NWNWNNNWN
19	J	NNNNWWWNN	41	+	NWNNNWNWN
20	K	WNNNNNNWW	42	%	NNNWNWNWN
21	L	NNWNNNNWW	n/a	*	NWNNWNWNN

 

The Extended Code 39 Encoding Table

 

 

Value	ASCII	Code 39	Value	ASCII	Code 39	Value	ASCII	Code 39	Value	ASCII	Code 39
0	NUL	%U	32	SP	Space	64	@	%V	96	`	%W
1	SOH(Start of Heading)	$A	33	!	/A	65	A	A	97	a	+A
2	STX(Start of Text)	$B	34	“	/B	66	B	B	98	b	+B
3	ETX(End of Text)	$C	35	#	/C	67	C	C	99	c	+C
4	EOT(End of Transmission)	$D	36	$	/D	68	D	D	100	d	+D
5	ENQ (Enquiry)	$E	37	%	/E	69	E	E	101	e	+E
6	ACK (Acknowledge)	$F	38	&	/F	70	F	F	102	f	+F
7	BEL(Bell-Audible of Attention Signal)	$G	39	‘	/G	71	G	G	103	g	+G
8	BS(Backspace)	$H	40	(	/H	72	H	H	104	H	H
9	HT(Horizontal Tabulation)	$I	41	)	/I	73	I	I	105	i	+I
10	LF(Line Feed)	$J	42	*	/J	74	J	J	106	j	+J
11	VT(Vertical Tabulation)	$K	43	+	/K	75	K	K	107	k	+K
12	FF(Form Feed)	$L	44	,	/L	76	L	L	108	l	+L
13	CR (Carriage Return)	$M	45	–	–	77	M	M	109	m	+M
14	SO (Shift Out)	$N	46	.	.	78	N	N	110	n	+N
15	SI(Shift In)	$O	47	/	/O	79	O	O	111	o	+O
16	DLE (Data Link Escape)	$P	48	0	0	80	P	P	112	p	+P
17	DC1(Device Control 1-XON)	$Q	49	1	1	81	Q	Q	113	q	+Q
18	DC2 (Device Control 2)	$R	50	2	2	82	R	R	114	r	+R
19	DC3(Device Control 3-XOFF)	$S	51	3	3	83	S	S	115	s	+S
20	DC4 (Device Control 4)	$T	52	4	4	84	T	T	116	t	+T
21	NAK(Negative Acknowledge)	$U	53	5	5	85	U	U	117	u	+U
22	SYN(Synchronous Idle)	$V	54	6	6	86	V	V	118	v	+V
23	ETB (End of Transmission Block)	$W	55	7	7	87	W	W	119	w	+W
24	CAN (Cancel)	$X	56	8	8	88	X	X	120	x	+X
25	EM (End of Medium)	$Y	57	9	9	89	Y	Y	121	y	+Y
26	SUB (Substitute)	$Z	58	:	/Z	90	Z	Z	122	z	+Z
27	ESC(Escape)	%A	59	;	%F	91	[	%K	123	{	%P
28	FS(File separator)	%B	60	<<	%G	92	\	%L	124	|	%Q
29	GS(Group Separator)	%C	61	=	%H	93	]	%M	125	}	%R
30	RS(Record Separator)	%D	62	>	%I	94	^	%N	126	~	%S
31	YS(Unit Separator)	%E	63	?	%J	95	_	%O	127	DEL	%T

CODE 93 SYMBOLOGY

 

CODE 93 INTRODUCTION

Code 93 is an alphanumeric, continuous, variable-length symbology,it can encode the full ASCII character set. Code93 is used primarily by Canadian postal office to encode supplementary delivery information. Every symbol includes two check characters.Code 93 is similar to Code 39. It encodes 47 characters.Every code 93 symbol must include two check characters.

CODE 93 ENCODING TABLE

VALUE	CHARACTER	VALUE	CHARACTER
0	0	24	O
1	1	25	P
2	2	26	Q
3	3	27	R
4	4	28	S
5	5	29	T
6	6	30	U
7	7	31	V
8	8	32	W
9	9	33	X
10	A	34	Y
11	B	35	Z
12	C	36	–
13	D	37	.
14	E	38	SPACE
15	F	39	$
16	G	40	/
17	H	41	+
18	I	42	%
19	J	43	$ Replace
20	K	44	% Replace
21	L	45	/ Replace
22	M	46	+ Replace
23	N	–	* Start/Stop

Code 93 can encode 128 Full ASCII character, if the character is not included in the above table, then you need to encode it using the $, /, %, and + symbols as “shift” characters in the Extended Encoding Table.It is the same with the Code 39 Extended Encoding Table. Note that the characters $ ,% , / , and + in Code 93 Extended Encoding Table should use the replace one in above table.

Code 93 Check Digits Calculation

 

1. Take the value (0 through 47) of each character in the barcode (see the table to the left). The start and stop characters are not included in the checksum calculation.

    

2. Assign the weight for each character. The right-most character has a weight value of 1, the second to last 2 and so on. After 20, the sequence goes back to 1.

    

3. Multiply the character value with weight. Sum all the results.

    

4. Divide the result by 47 and get the remainder. Reverse look up the remainder to get the character. This is check character “C”.

    

5. Append the “C” character at the end of the data, and repeat the step1 through step 4. This time the weight ranges from 1 to 15. The result is the character “K”.

    

 

Example: “EaseSoft”, the “C” checksum would be calculated as follows:

Thus the sum of the individual weighted sums is 3168. Modulo 47 gives a value of 67 with remainder 19. The value 19is associated with the J, so the “C” check character is ‘J’..

The “K” checksum character is calculated in basically the same way except that the weighting goes from 1 to 15. Also, the right-most character is now the “C” checksum character which was calculated in the step above.

STRING	E	+Replace	A	+Replace	S	+Replace	E	S	+Replace	O	+Replace	F	+Replace	T	J
VALUE	14	46	10	46	28	46	14	28	46	24	46	15	46	29	19
WEIGHT	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1
WEIGHTED SUM	210	644	130	552	308	460	126	224	322	144	230	60	138	58	19

Thus the sum of the individual weighted sums is 3625. Modulo 47 gives us a value of 77 with a remainder of 6. The value 6 is associated with the ASCII character “6”, so the “K” check character would be encoded using the “6” symbol encodation from the table above.

STRUCTURE OF A CODE 93 BARCODE