I am trying to generate a UPC Formatted Barcode. Clients file stores the 12 digit number and when I send it through my report using the UPC Font, it does not seem to look right. Anyone with some hints would be greately appreciated. I think that there is somehting to do with a checkdigit , but not sure… HELP!!! Darren Bezzant, NCPS, NCSD Central Software Ludlow, New Brunswick, Canada dbz@nb.aibn.com
Could you be more specific about this UPC code? How is it encoded: Code128 with checksum? How do you implement the Barcode in your report? Do you have a TrueType font or are you sending the code to print as pure text with the appropriate escape sequences for the barcode printer? Marcus Marcus Fabian phone: +41 79 4397872 m.fabian@thenet.ch
I infer that you are using UPC-A format. In which case, yes, there is a check digit which is added on the end. UPC-A is essentially the same as EAN13 except that all UPC codes begin with a zero. They are sometimes stored as 11 digits in which case you have to add the leading zero. The checksum calculation you need is: CV := STRCHECKSUM(Source,‘131313131313’,10); Where Source is your 12 digit string and CV is the check digit. I was going to say that you need to remember that the lead digit determines the pattern for the first 7 digits of the code but since all your numbers will begin with zero … You will also need to remember to add in codes for the lead, centre & tail guard bars before printing. John
Sorry to take so long to get back to this… John, you had said: You will also need to remember to add in codes for the lead, centre & tail guard bars before printing How exactly to I do this. All I have been provided is a 12 digit number, some starting with 7 others starting with 0. Any help would be greatly appreciated.
some barcodes just need a * either side of the string you are sending… perhaps UPc fonts have a similar requirement Craig Bradney Project Manager - Technical Navision Solutions & Services Deloitte Growth Solutions Deloitte Touche Tohmatsu P:+61-2-9322-7796 F:+61-2-9322-7502 E:craig_bradney@deloitte.com.au
As Craid said, some barcodes need extra bits around the characters being encoded to identify where the code begins and ends and also in which direction the code is being scanned (left-right or right-left). EAN/UPC codes normally have some bars extending below the main body of the code. These are the guard bars. It depends on the actual barcoding font you are using but with mine I have to work out a character which depends on the first digit of the code in order to find the start guard Then I add the first six digits of the code which is tricky because each digit has two different patterns of bars & spaces and the pattern of these are used to encode the first digit. Now add a / as the centre guard, the last six digits (including the 13th check digit) and finish off with a + for the end guard. I can now print the code with the font. Hope this makes sense. Let me know if you need more help. John