Converting one barcode to another barcode

[zorbital]

Hi,

I need to read the old barcode, compare it in a database where I've stored the old and the new barcodes, export the new barcode and print it. Is is possible?

[Stewart Ross]

Hi, and Welcome to Bytes!

Short answer is that yes it is possible to do what you say, but since you leave out more than you tell us we can't guide you other than in generalities.

Firstly, if by 'read in' you mean scan the current barcode manually, then in general any barcode reader can do this. What is input to the database by the reader is the value of the barcode.

I assume you have a lookup table already built which provides the new barcode value given the old.

Not sure what you mean when you say you need to 'export' the barcode. If it is as a graphic this is not straightforward - it is possible, but there are no in-built facilities in Access to create the graphic.

Similarly, printing barcodes is possible but not straightforward . You can use a bar-code font - but then every PC using your application would need to have the font installed. Applications which print barcodes as graphics are available (which will also export the barcode in a graphics format such as WMF), but as these are commercial applications you would need to pay for one.

There are several different types of barcode. You don't say what type you are referring to, so there is little more I can add to this general reply at this stage.

-Stewart

[youmike]

To amplify what Stewart says, you need to remember that a printed bar-code is simply a way of representing an underlying character string (usually a number) with extra characters (checksum digits) to permit verification when read added by the bar-code printing process.

As Stewart says, a bar-code reader connected to a PC and use in an Access application returns the underlying number only - it interprets the bar-code by applying a defined translate routine built into the scanner firmware. Windows interprets such a scanner as a keyboard device.

To print a bar code, the commercial font packages do the opposite: they take the number and apply a routine to add the checksum digit, then convert the number into a graphic conforming to international standards. As Stewart says, you could design your own software to translate a number into a bar-code, but I'd say it's just not worth the effort. An internet search will find dozens of bar-code fonts and the prices are not necessarily astronomic. I'd suggest that you get a set for which you have to pay. There may well be free fonts, but use them with caution, testing before you go live.

[Stewart Ross]

Youmike is spot-on with his reply. I use a free 3-of-9 barcode font which meets my needs (relating in this case to producing student survey forms which are barcoded with the student ID, as per the mailmerged Word example shown in the screenshot).

In investigating some of the 3-of-9 fonts available some of them were of variable readability; I did a lot of testing before settling on the one I use, which I found readable at a wide variety of print sizes.

3-of-9 barcodes are common, but the other types of barcode are not generally found in free fonts. I should have added, as youmike pointed out, that pay-for bar code generators are not necessarily expensive - and some are available as ActiveX control add-ons which can be used like any other control from Access and other apps.

-Stewart

[youmike]

Having looked at Stewart's example, I'd just add one thought about choice of font. Apart from specifying the width and spacing of the bars, the 3 of 9 spec also prescribes where the human readable numbers should fall in the image and the size of start and end characters which have to be included in the string. Look at any packet in your grocery cupboard and you'll see what I mean. When choosing your font, check that it complies. Best way to do this is to try sample print-outs on a couple of scanners.