Bad Code128 Your barcode does not scan. Whomever it was that notified you, however and whenever the bad news arrived, it is a stressful surprise.  What happened? What do I do next?

Scanners—especially imager scanners, are very aggressive and tolerant of bad barcodes.  Older laser scanners are less forgiving. The first thing to do is get live samples of  the  problem barcodes if possible; alternatively get samples from the same batch or print run. The very next thing to do is locate and calibrate a barcode verifier. It is important to use  an ISO compliant verifier—one that tests and graces the full set of ISO parameters.

 

If a scanner cannot read the barcode, how can a verifier read it?

Some verifiers have the ability to lower the reflectance difference threshold to “force” a decode. No verifier can grade a barcodescan0001_A_Conicelli_Horrible_1.4mmNR without first decoding it: this capability makes it possible to test the barcode and identify what attribute is downgrading the barcode—and that is key in identifying the cause of the problem.

If the verifier cannot decode and grade the barcode, visual inspection is the only remaining option. Using a low power (8-12X) magnifier, find the X dimensions (narrow bars) in the symbol. How do they compare to the narrow widths? Are they approximately equal? Are the narrow widths clearly intact or are they barely there? Average bar gain is a common cause of barcode failure. Are the quiet zones intact? Another common reason for decode failure is quiet zone encroachment. These are not just 1D barcode issues: 2D symbols also have X dimensions (modules) and full-surround quiet zones, and are likewise vulnerable to press or dot gain as well as other distortions that can keep them from decoding.

Check the Decode

If the verifier does seem to decode the barcode, make sure the human readables match the encoded data. Also, check to see if the symbology is the correct type. Sometimes verifiers can mis-decode a very bad barcode for reasons discussed above. If the verifier did correctly recognize the barcode, see which ISO parameter is most responsible for downgrading the final grade. More than one parameter might be involved. Also see if there is a structural problem such as an incorrect check digit. There could also be a data formatting error—for example a barcode that is the correct symbology but not compliant to the GS1 data structure. If the scanning environment is GS1 compliant, the scanners may be programmed to accept only GS1 compliant data—and therefore failing to decode these barcodes.

If you get a successful decode and a grade from the verifier, the ISO parameters point you to the cause of the problem and therefore the path to a solution. Halleluiah, a problem with a known cause. If you do not understand what the ISO parameters mean, we have two great little booklets that can help you figure it out—one for 1D, another for 2D. Click the link, sign into the website and download all the copies you want.

Please comment and add your own experiences or ideas to t his conversation.

 

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3db Barcode Testimonial

Our company (an advanced software company) recently worked with Barcode Test to source a barcode verifier.  Not long ago, we were awarded a contract requiring products to be marked with IUIDs in accordance with MIL-STD-130.  For that standard, marking labels must pass a verification test that evaluates many variables (contrast, size, clarity, syntax, modularity, and more).  After a thorough search, we reduced our options to a select few.

In our search for a verifier, the Axicon line caught our attention.  Barcode Test is our regional reseller for this product.   From the beginning, they were very prompt with their responses.  We ended up having a quick call with John Nachtrieb to go over our needs.  John was extremely easy to work with and provided a lot of great information.  He was very knowledgeable on the matter and was quick to offer up a demo unit (free of charge).

Upon receiving the demo verifier and testing it, a few questions arose.  John joined a call with us and answered all our questions.  Ultimately, the Axicon verifier wasn’t the best fit for us, so we shipped the demo back.  John was completely understanding.  A few weeks later, Barcode Test reached back out with another possible verifier for us to try.  While they didn’t sell that brand, they just wanted to help us find the best option that met our needs. They even offered to send us the unit that they have in-house to see if it worked to our liking. 

Barcode Test is truly a great company to work with.  Their service and willingness to help the customer are far beyond what you typically get from other companies.  They are experts in barcode quality assurance and seem willing to help in any way they can (even if that means not getting a sale and recommending another option that better fits the customer’s needs).  If anyone is in the market for barcode verification/scanning services or products, I would highly recommend giving Barcode Test a call.

Regards,

Production Manager