周杰伦的病能活多久CODABAR码编码方式

2020年12月10日发(作者：武立勋)
CODABAR SYMBOLOGY
(
Monarch, NW-7, USD-4, 2 of 7 code
)


CODABAR BACKGROUND INFORMATION
Codabar was developed was developed in 1972 Pitney Bowes, Inc. It is a discrete,
self-checking symbology that may encode 16 different characters, plus an additional 4
startstop characters. This symbology is used by U.S. blood banks, photo labs, and on FedEx
airbills.
A typical Codabar barcode is:

Since Codabar is self-checking, there is no established checksum digit. Should a specific
application wish to implement a checksum digit for additional security, it is up to the
implementer to define and handle same. However, keep in mind that other applications that
read your barcode will interpret your checksum digit as part of the message itself.
ENCODING THE SYMBOL
In the following text, we will discuss the encoding of the barcode by considering that the
number a whereas a a

(11), followed by a single-wide space (0), followed by a single-wide bar (1). This would be
printed in the barcode as:


STRUCTURE OF A CODABAR BARCODE
A Code 11 Barcode has the following structure:
1. One of four possible start characters (A, B, C, or D), encoded from the table below.
2. A narrow, inter-character space.
3. The data of the message, encoded from the table below, with a narrow inter- character
space between each character.
4. One of four possible stop characters (A, B, C, or D), encoded from the table below.
CODABAR ENCODING TABLE
This table indicates how to encode each digit of a Codabar barcode. Note that the
Encoding
the Encodingcolumn represents how the barcode will actually be encoded as
described above in
For example, the character 0 is defined as
narrow space, narrow bar, narrow space, narrow bar, wide space, wide bar
to 101010011 in the
used to express barcode formats in other documents on this site.
ASCII
0

1

2

3

4

5

6

7

8

9

- (Dash)

$$

: (Colon)

(Slash)

. (Point)

+ (Plus)

StartStop A

WIDTH
0000011

0000110

0001001

1100000

0010010

1000010

0100001

0100100

0110000

1001000

0001100

0011000

BARCODE
101010011

101011001

101001011

110010101

101101001

110101001

100101011

100101101

100110101

110100101

101001101

101100101

CHARACTER

ENCODING

ENCODING

1000101

1101011011

1010001

1101101011

1010100

1101101101

0010101

1011011011

0011010

1011001001

StartStop B

StartStop C

StartStop D

0001011

1001001011

0101001

1010010011

0001110

1010011001

NOTE 1: Since the first and last element of every character is always a bar, a narrow
space is appended at the end of each character to separate the last bar of a character
from the first bar of the character that follows.
NOTE 2: Codabar is interesting in that there are always 4 bars and 3 spaces of
varying sizes, but the total size (width) of a character varies depending on the
character being encoded.
CODABAR ENCODING EXAMPLE
We will now code the example barcode from above, A40156B. Of course, the
'A' StartStop character and the 'B' refers to the 'B' StartStop character.
1. The 'A' STARTSTOP character: 1011001001.
2. An intercharacter space encoded as 0.
3. The digit 101101001.
4. An intercharacter space encoded as 0.
5. The digit 101010011.
6. An intercharacter space encoded as 0.
7. The digit 101011001.
8. An intercharacter space encoded as 0.
9. The digit 101101001.
10. An intercharacter space encoded as 0.
11. The digit 100101011.
12. An intercharacter space encoded as 0.
13. The 'B' STARTSTOP: enocded as 1010010011.
This is shown in the following graphical representation where the barcode has been
sectioned-off into areas that reflect each of the 13 components just mentioned. However, the
inter-character spacing are not numbered, only the actual characters.

STRUCTURE OF FEDEX AIRBILL BARCODES
FedEx airbills have barcodes that are encoded using Codabar. Presumably to insure complete
accuracy, FedEx has chosen to implement a checksum digit even though it is technically not
necessary with Codabar.
A FedEx airbill number has the format of XXXX-XXXX-XXXY with an additional 4-digit
IDZZZZ).
The X's represent digits of the airbill number. They are presumably sequential and probably
unique. The Form ID (ZZZZ) is included in the barcode but isn't technically part of the airbill
number--you can perform airbill tracking with just the first 12 digits. The
be a checksum value.
The barcode itself consists of a 'C' Start Code, followed by the 16 digits of data
XXXXXXXXXXXYZZZZ, followed by a final 'D' Stop Code.
At this point, it hasn't been determined the formula used to calculate the checksum digit. The
checksum digit (Y) forms part of the airbill number and is embedded in the middle of the
barcode data, but may or may not include the
calculation.
NOTE: If you have information regarding the process that FedEx uses to calculate the
check digit, please let us know so we can add this information to this page.