code-128

Details on the barcode type.

Code 128 can be used to encode ASCII text of variable length. For this purpose characters can be selected from three character sets, each containing 106 characters. This table lists the available characters in the character sets A, B and C:

Table 1. Available characters in the character sets A, B, and C.
Reference Number	Character Set A	Character Set B	Character Set C
0	SP	SP	00
1	!	!	01
2	"	"	02
3	#	#	03
4	$	$	04
5	%	%	05
6	&	&	06
7	'	'	07
8	(	(	08
9	)	)	09
10	*	*	10
11	+	+	11
12	,	,	12
13	-	-	13
14	.	.	14
15	/	/	15
16	0	0	16
17	1	1	17
18	2	2	18
19	3	3	19
20	4	4	20
21	5	5	21
22	6	6	22
23	7	7	23
24	8	8	24
25	9	9	25
26	:	:	26
27	;	;	27
28	<	<	28
29	=	=	29
30	>	>	30
31	?	?	31
32	@	@	32
33	A	A	33
34	B	B	34
35	C	C	35
36	D	D	36
37	E	E	37
38	F	F	38
39	G	G	39
40	H	H	40
41	I	I	41
42	J	J	42
43	K	K	43
44	L	L	44
45	M	M	45
46	N	N	46
47	O	O	47
48	P	P	48
49	Q	Q	49
50	R	R	50
51	S	S	51
52	T	T	52
53	U	U	53
54	V	V	54
55	W	W	55
56	X	X	56
57	Y	Y	57
58	Z	Z	58
59	[	[	59
60	\	\	60
61	]	]	61
62	^	^	62
63	_	_	63
64	NUL	`	64
65	SOH	a	65
66	STX	b	66
67	ETX	c	67
68	EOT	d	68
69	ENQ	e	69
70	ACK	f	70
71	BEL	g	71
72	BS	h	72
73	HT	i	73
74	LF	j	74
75	VT	k	75
76	FF	l	76
77	CR	m	77
78	SO	n	78
79	SI	o	79
80	DLE	p	80
81	DC1	q	81
82	DC2	r	82
83	DC3	s	83
84	DC4	t	84
85	NAK	u	85
86	SYN	v	86
87	ETB	w	87
88	CAN	x	88
89	EM	y	89
90	SUB	z	90
91	ESC	{	91
92	FS	\|	92
93	GS	}	93
94	RS	~	94
95	US	DEL	95
96	FNC3	FNC3	96
97	FNC2	FNC2	97
98	SHIFT	SHIFT	98
99	CODEC	CODEC	99
100	CODEB	FNC4	CODEB
101	FNC4	CODEA	CODEA
102	FNC1	FNC1	FNC1
103	STARTA	STARTA	STARTA
104	STARTB	STARTB	STARTB
105	STARTC	STARTC	STARTC
-	STOP	STOP	STOP

The code value is expected as a comma-separated list of character names. It must start with a character set selection character STARTA, STARTB, or STARTC and must end with a checksum character followed by the STOP character. If these characters are omitted then the system calculates the checksum automatically and adds the required STOP character.

The control characters CODEA, CODEB and CODEC can be used to switch from one character set to another.

The control character SHIFT changes the character set for the immediately following character from A to B and vice versa.

EAN 128 bar codes can be drawn using this bar code type. Valid EAN 128 codes start with the sequence "STARTC,FNC1". What follows is a sequence of data packets. Each packet starts with a one digit application identifier (AI) from the C character set. The AI is followed by data. The type and amount of expected data is AI specific. The amount can be fixed or variable. In the case of variable amount of data, the end of the data must be indicated by a FNC1 character. Here is a table with some common AIs.

Table 2. EAN 128 Bar Code Common AIs
AI	No of Data Characters	Description
00	18	Identification of a delivery unit
01	14	An EAN 13 Number including check digit
10	up to 20 alphanumeric characters	Shipping batch identifier
11	3	Production date in the format YYMMDD

The complete list of AIs is country specific and is maintained by the local EAN organization. The textual representation requires AIs to be enclosed in round braces. Examples:

Table 3. EAN 128 Bar Code textual representation
Textual representation	code value	Remark
(25)03x57	STARTC, FNC1, 25, 03, CODEB, x, 5, 7	Note that although, it is a variable length AI, no FNC1 is added at the end in the case when the AI is the last one.
(30)19(21)3456789012	STARTC, FNC1, 30, 19, CODEA, FNC1, CODEC, 21, 12, 34, 56, 78, 90, 12	Note that switching to code a is not necessary, as FNC1 exists in all three character sets.

If a code contains the control character FNC2 then the decoder does not transmit this value. Instead it appends the value to an internal storage. Only after the decoder encounters a value not containing the FNC2 control character, the decoder transmits the temporary storage and the value read. The temporary storage is then cleared. The purpose of this mechanism is to allow the breaking of long text sequences into several lines.

The effects of the control characters FNC3 and FNC4 are decoder specific.

Decoders remove the character STARTA, STARTB, STARTC, CODEA, CODEB, CODEC, SHIFT, FNC1, FNC2, FNC3, FNC4, STOP, and the checksum character from the data before displaying or transmitting the value.

The last but one character is the checksum character that is calculated as follows:CS=(Ref(1)+Sum(i=2 to n of (i-1)*Ref(i))) mod 103 where Ref(i) is the reference number of the character i, and n is the total number of characters. Example: codeValue="STARTB,A,B,C"CS=(104+(1*33)+(2*34)+(3*35)) mod 103,CS=310 mod 103,CS=1 Looking up reference number 1 in character set B yields the exclamation mark '!' character. The full code value including checksum and stop character is therefore: codeValue="STARTB,A,B,C,!,STOP"

The nominal height is 6.5mm. The width of the bar can be calculated using this formula: L/mm=(5.5Nc+11Nab+35)*0.19 where Nc is the number of characters from character set C and Nab denotes the number of characters from character sets A and B. On each side of the bar area 1.9mm padding is added.