I am trying to come to terms with how a barcode is decoded and generated by a scanner.
A note from the client says the following generated bar code consists of extra characters:
Generated Code: |2389299920014}
Extra Characters: Apparently the first two and last three characters are not part of the bar code.
Question
Are the extra characters attached by the bar code reader (therefore dependent on the scanner) or are they an intrinsic part of the barcode?
Here is a sample image of a barcode:
http://imageshack.us/a/img824/1862/dm6x.jpg
Thanks
[SOLVED] My apologies. This was just another one of those cases of 'shooting your mouth off' without doing proper research.
Solution The code is EAN13. The prefix and suffix are probably scanner dependent. The 13 digits in between are as follows (first digit from the left) Check Sum (Next 9 digits) Company Id + Item Id (Last 3 Digits ) GS1 prefix
It's hard to answer without understanding what format you are trying to encode, what the intended contents are, and what the purported contents are.
Some formats add extra information as part of the encoding process, but it does not become part of the content. When correctly encoded and decoded, the output should match the input exactly.
Barcodes encode what they encode and there is no data that is somehow part of the barcode but not somehow encoded in it.
EAN-13 has no scanner-dependent considerations, no. The encoding and decoding of a given number is the same everywhere. EAN-13 encodes 13 digits, so I am not sure what the 13 digits "in between" mean.
You mention GS1, which is something else. A family of barcodes in fact. You'd have to say what specifically you are using. The GS1 encodings are likewise not ambiguous or scanner-dependent. You know what you want to encode, you encode it exactly, it's read exactly.
Related
There is a service hosted on for generating barcodes metafloor.com using bwip.js
I want to generate a barcode for following data (GS character is represent by {GS}).
(01)10875066000333(10)1212{GS}(17)121212(30)8{GS}
According the documentation I'm able to generate a barcode for data without GS character
https://bwipjs-api.metafloor.com/?bcid=gs1-128&text=(01)10875066000333(10)1212(17)121212(30)8
But the scanner require GS characters.
The documentation is clear
Special characters must be encoded in format ^NNN
Parse option has to be true, by using parsefnc parameter
The parameter has to be URL-encoded.
So for my string it's:
https://bwipjs-api.metafloor.com/?bcid=gs1-128&text=(01)10875066000333(10)1212%5E029(17)121212(30)8%5E029&parsefnc
But this gives me Error: bwipp.GS1badCSET82character: AI 10: Invalid CSET 82 character.
I also tried
Send GS char directly as %1D
Send GS char as %5EGS
Send GS char as ^029
Send GS char directly
Set parsefnc=true
Combination of all above
But still getting the same error.
Is there something I'm doing wrong or is the problem on the other side?
For GS1 Application Identifier based data, trust the library to encode the data correctly by selecting the GS1-specific encoder for the symbology (gs1datamatrix in this case) and then provide the input in bracketed AI notation, i.e. without FNC1 / GS separators.
The encoder will automatically add all of the necessary FNC1 non-data characters (which are transmitted as ASCII GS characters when read by a scanner) and it will also validate the contents of the AI data that you supply.
Users that select a generic symbology and then attempt to perform the AI encoding themselves are prone to making several mistakes:
Omitting the required FNC1 in first position.
Omitting the required FNC1 separators at the end of AIs with no pre-determined width.
Terminating pre-defined length AIs with unnecessary FNC1 characters.
Terminating the message with an unnecessary FNC1 character.
Encoding ASCII GS data characters instead of the canonical FNC1 non-data characters.
Including illegal, literal parentheses to denote the AIs.
Providing improperly formatted or invalid AI values.
Omitting requisite AI attributes.
Including mutually-exclusive AI pairings.
Many of these mistakes will result in failure to decode and interpret the GS1 AI data (even if the barcode appears to read successfully) which may result in charge-backs and necessitate relabelling or disposal.
The data that you are providing falls afoul of at least some of these pitfalls.
See this article for a thorough description of the checks that BWIPP (and hence BWIP-JS) implements to prevent such data quality issues.
I am writing some code to parse GS1 barcodes. There are a few App Idents (AIs) in the specification that I don't understand. For example, AI 426 (https://www.gs1.org/standards/barcodes/application-identifiers/426?lang=en):
This is saying that the data must be 3 digits (the app ident) followed by another 3 digits for the country code (e.g. 426824). As such it is a fixed length field. The bit I don't understand is that it also says it requires a FNC1 delimiter. Surely if it is a fixed length field it won't require a delimiter after the data? Can anyone shed any light as to why the specification says this, or is it likely to be a mistake?
In the past, we've used ZPL to create Code39 barcodes with a TAB character encoded in the middle using something similar to the following:
*USERNAME$IPASSWORD*
The $I in the middle gets translated to a TAB by the barcode scanners we use.
Now we have a need to do the same thing, but using Code128. With Code39, all the text needs to be uppercase (unless you're using Code39Extended, which supports lowercase letters). Because some of the data that is going to be encoded will be lowercase, we need to use Code128 B for most of the barcode, switching to Code128 A in the middle to encode the TAB character, then back to Code128 B for the final part.
Looking through the "ZPL II Programming Guide", it should be as easy as:
>:username>7{TAB}>6PA55w0rd
The >: at the beginning sets the subset to B, the >7 changes the subset to A, and the >6 changes the subset back to B. The problem I'm having (and haven't found a solution after almost a week of searching) is: How do I encode a TAB character using only text?
Use the ^FH (field hexidecimal encoding) command immediately prior to your field data. Based on your example:
^FH_^FD>:username>7_09>6PA55w0rd^FS
Where the underscore '_' is used as the escape character and 09 is the hex value for tab.
Also note that if the chosen escape character appears in the user name or password, you will need to escape it as well.
I tried what Mark Warren suggested, but unfortunately, it didn't work. It did, however, get me looking back through the ZPL II Programming Guide and I found the following, which I had overlooked before:
Code 128, Subsets A and C are programmed in pairs of digits, 00 to 99, in the field data string.
...
In Subset A, each pair of digits results in a single character being encoded in the bar code...
So, since 73 equates to a TAB in Subset A, I tried the following:
>:username>773>6PA55w0rd
And it worked!
I am trying to print a Code 128 barcode on a label using the following the piece of ZPL with a Zebra ZP 450 printer:
^BY3^BCN,112,N^FO090,660^FD>;>89102100^FS
I'm expecting the barcode to scan as "9102100". However, when I scan the printed barcode, it reads as "910210" -- cutting off the final digit.
If I change the last digit, it is still cut off. But if I add more digits onto the end, e.g. "9102100357", the barcode correctly reads as "9102100357".
Why am I "losing" a digit in this particular case?
The >; inside of your ^FD block is telling the code 128 barcode to go into a subset (subset C in this case) which forces the data in the barcode to be numeric pairs (00 - 99). Any data that is not supplied in numeric pairs is ignored. If you put a letter in there, it will ignore that pair. In your case 9102100 has an odd number of numbers, so it ignores the last one. If for example, you add another 0, it will put all the letters in the barcode.
The ;> which puts the barcode in Subset C is not the default. Subset B or :> is the default which will allow any character to be encoded in the barcode. So you can replace the ;> with :>, or just remove the ;> entirely, and it will print out properly.
Check out the ^BC documentation in the ZPL programming manual for more information about Code 128 subsets and data validation
See pg 92 of the ZPL Programming Guide.
This issue may have been fixed in the firmware update, see below:
Example: This is an example with the mode parameter set to D*:
^XA
^PON
^LH0,0
^BY2,2.5,145
^FO218,343
^BCB,,Y,N,N,D
^FD(91)0005886>8(10)0000410549>8(99)05^FS
^XZ
D* — When trying to print the last Application Identifier with an odd number of characters, a problem
existed when printing EAN128 bar codes using Mode D. The problem was fixed in firmware version
V60.13.0.6."
I have to generate QRCodes using concatenated object properties. These strings might be long, that's why I'd like to know which compression algorithm to use knowing that my String's length is between 25 an 100+ characters
thanks in advance,
Jerec
I am assuming that since you are going to use compression before you store the strings that these QR codes will not be readable by any client, it would have to be an application that you wrote (b/c you are storing character with an unknown encoding, the client won't be able to decode).
Instead of compressing and storing the long string in the QR code, have your application create a URI (like a GUID or a URL) and when your application decodes that URI it looks up all the values (uncompressed) that you wanted to store in the QR code. Then your app can just look up the format in any way it wants.
For example, assuming your persistant storage is an xml file, but it could be anything:
<URI = "http://mydomain.com/790C9704-8C61-435F-991D-CDBB5767AA3D">
<MyElement>14523</MyElement>
<MyElement>67548</MyElement>
...
<MyElement>46167</MyElement>
</URI>
Encoded on QR code: "http://mydomain.com/790C9704-8C61-435F-991D-CDBB5767AA3D", values can then be looked up.
The algorithm used to encode QR codes is dependent on the type of data you encode. See http://www.swetake.com/qr/qr1_en.html.
If you know, for example, that you always have the same number of digits per id and therefor could just string them together without punctuation, you can encode them as purely numeric and you'll use 10 bits for every three characters.
If you need some kind of separator, if you use something in "0-9A-Z $%*+-./:", you'll stay alphanumeric and get 2 characters in 11 bits.
If you give it arbitrary data (note that this includes any lower case: the list above does not include lower case letters) you're going to be using 8 bits per characters.
So numeric only would end up being 60% smaller.