BARCODES 201 JOHN NACHTRIEB

Transcription

1 BARCODES 201 JOHN NACHTRIEB

2 TABLE OF CONTENTS INTRODUCTION 1 Why are there Different Kinds of Barcodes? 2 My Barcode Does Not Scan--Why? 5 How Do Barcodes Work? 8 The Ten Worst Barcode Bloopers 12 Barcode Validation the Newest Barcode Quality Attribute 16 About The Author 19

3 This Page Is Intentionally Blank

4 INTRODUCTION Barcodes 201 is written for someone who knows more than the average person about this fascinating technology, and wants to know more. They know that there are many different kinds of barcodes, and wants to know why. There is a logical and interesting reason! It is one thing when a barcode doesn t work well perhaps the print quality is substandard, and maybe the scanner isn t working right. But what do you do when the barcodes doesn t work at all How do you investigate the problem to get to a solution, without thrashing around with trial-and-error and wasting a lot of time? How do barcodes actually work? It s pretty simple and devilishly clever. While perfect barcodes are what we say we always want, bad barcodes are so much more interesting! This topic has been addressed in our weekly blog before, and this update has uncovered some real disasters. Always a fun topic as long as the bad barcodes aren t on our product! Finally, Barcode 201 discusses barcode validation what does it mean and why is it important? Barcodes 201 1

5 WHY ARE THERE DIFFERENT KINDS OF BARCODES? Having discussed what barcodes are and what they do a natural next question is, why are there different kinds of barcodes? Isn t there one symbology that could do it all? Barcode technology may be approaching that landmark but there is a path that got us to this point. The milestones on that path are in fact the different symbologies that have been invented; consistent with the theme of the previous article referenced above, symbologies were created to solve specific problems. While this seems painfully obvious, what may not be so obvious are the pain points in that evolutionary process. One example is staring us all in the face: the global UPC system. It solved a problem in the 1970 s but is now threatened by its own success as the system runs out of numbering capacity. A less obvious example is the GS1 Databar Stacked Omnidirectional symbols we all see on loose fresh produce such as apples and oranges. We are all familiar with them but have you ever seen them scanned? They are a massive 2 Barcodes 201

6 failure and this is another part of the evolutionary process. The evolutionary process in barcoding is driven by three factors: data type, data capacity and symbol size. There is an underlying, foundational fourth driver: even if it satisfies the preceding three factors, a symbology must solve a problem. Fresh produce Databar labels failed because they solved a problem that didn t exist. There are basically two data types: numeric and alpha-numeric. Serial number applications are perfect for numerical-only symbologies like UPC/EAN and its cousin, the Interleaved 2 of 5 symbology. Alpha-numeric symbologies can parse subsets of data representing specific attributes of the marked item: serial number, lot or batch, expiration date, etc. For database look-up like what UPC does, numeric-only works just fine if you have enough data capacity to serve the huge and growing population of products in a global commerce environment, which brings us to the second factor. Data capacity and symbol size are related the more data, the larger and denser the symbol. Where larger capacities are necessary linear barcodes have evolved into symbologies with greater encoding efficiencies. Code 128, for example, can encode pairs of characters in the same space required to encode single characters. Symbol size can also be minimized somewhat by decreasing the size of the X dimension (narrow bar or space) and decreasing the wide/narrow ratio of a binary symbology, but there are tradeoffs in the barcode s tolerance of print inaccuracies. Barcodes 201 3

7 The most recent step in the evolutionary process is 2D or matrix symbologies, which have full alpha-numeric encoding capability, much greater data capacity than 1D barcodes and a more manageable square footprint. 2D symbologies are also more tolerant of print inaccuracies and offer user-definable error correction capability. Linear barcodes can only offer error detection. Given all of this, what is the absolute best barcode for you to adopt in your business? If you plan to stay in business, you should use what your trading partners use and migrate with them to whatever is next. 4 Barcodes 201

8 MY BARCODE DOES NOT SCAN--WHY? 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 grades the full set of ISO parameters. If a scanner cannot read the barcode, how can a verifier read it? Well, a verifier may not be able to read it, but if it can, it is because some verifiers have the ability to lower the reflectance difference threshold to force a decode. No verifier can grade a barcode 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 Barcodes 201 5

9 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. 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 under- 6 Barcodes 201

10 stand 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, to download all the copies you want. Barcodes 201 7

11 HOW DO BARCODES WORK? If you refer to all barcodes as UPC s, this article won t be interesting to you. But if you know that all barcodes are not UPC s, it may interest you to know that different symbologies encode the data very differently, and I m not talking about how the data itself is arranged: that s a different sort of difference. To be clear, we are talking about 1D or linear barcodes only; 2D or matrix symbologies are a whole different animal. At a very basic level, there are two types of barcodes: discrete and continuous. Discrete barcodes encode each character, whether an alphabetical character or a numerical character, well, discretely: clever description, eh? In other words, each character is its own little bar and space arrangement which is separated from the next encoded character by a non-intelligent (containing no information) space, called an inter-character gap. All bar-space combinations in continuous barcodes are meaningful: there are no dumb elements (space). Continuous barcodes are, in this way, more efficient that discrete barcodes. Barcodes encode data in elements (bars and spaces) of different widths. Some barcodes use only two widths narrow and wide to accomplish data encoding. These are called binary symbologies. The wide element is a fixed multiple of the narrow element width. Other barcodes utilize elements of three or four different widths, based on a common building block or module: these are called modular symbologies. 8 Barcodes 201

12 Another major distinguishing characteristic of barcodes is whether they are fixed or variable length; the description says it all. These are the basic distinctions in linear barcodes. From here the differences between symbologies get much more complicated and individualized. Here are some examples: Code 39 Code 39 is a discrete, binary, variable length barcode with the ability to encode numbers 0 through 9 and 29 upper case only alphabetical letters, plus a few special characters. Code 39 is said to be the most widely used barcode in the world which is counterintuitive considering all the UPC marked retail products in the global marketplace. Data is encoded in nine elements (bars and spaces), three of which are wide and the remaining six are narrow. The name Code 39 derives from this encoding scheme. UPC UPC is a continuous, modular, fixed length barcode; it encodes numerical characters only. Data is encoded in four elements: two bars and two spaces. Barcodes 201 9

13 Code 128 Code 128 is a continuous, modular, variable length barcode with the ability to encode the entire 128 character ASCII keyboard (but that is not how it got its name.). Code 128 encodes data in a combination of 6 bars and spaces (except for the check digit which is encoded in 7) Code 128 has three distinct data sets, A, B or C, which are defined by a prefix (A, B or C). Version A can encode numbers 0 through 9, alphabetical characters A through Z (upper case only), and a set of special characters such #, $, %, etc. Version B encodes the same special characters as A, 0-9 and the full alphabet in upper and lower characters. Version C encodes numerical only, and encodes them in pairs using the same 6 bars and spaces. This makes Version C very space-efficient if numerical only data needs to be encoded. ITF14 ITF14 is a continuous, binary, fixed length barcode which encodes numerals 0-9 only. 10 Barcodes 201

14 Data is encoded in five elements, two of which are wide. This accounts for the TF (two of five) part of the naming scheme. The I (interleaved) part of the name describes a very unique assembly of the bars and spaces: data encoded in the odd (first, third, fifth, etc.) positions in the barcode are encoded in bars only (two of them wide, three of them narrow). Data encoded in the even (second, fourth, sixth, etc.) positions in the barcode are encoded in spaces only (two of them wide, three of them narrow). Since encoded data is paired in this way, ITF14 must encode an even number of characters, and as the name also implies, that number is limited to 14 characters. Barcodes

15 THE TEN WORST BARCODE BLOOPERS The irony is that barcodes were invented to prevent errors. That is probably what makes barcode bloopers so interesting. What are the ten worst barcode bloopers since we last wrote about it a year ago? That is debatable and I invite you to agree or disagree with our choices but either way, submit your own candidates for worst barcode blooper at our sister site, BarcodesGoneWild. Since we re doing the talking, here are our choices for the ten worst barcode bloopers. By now we ve all probably seen barcodes that the creative team have had their way with. This is one of the worst because in their zeal to make it cute, they have destroyed the quiet zones, making it into.a waste of space. This QR Code has appeared in an auto dealer s ad month after month in a major US city newspaper. How long does it take before somebody realizes there is a problem and either fixes it or deletes it out of sheer embarrassment? 12 Barcodes 201

16 Full confession we re not familiar with this symbology. Please comment if you know what it is, but we are pretty sure few people could scan this with their smart phone. Why not just use a QR Code? Saving space is always a concern in packaging but this carries it to an extreme. This is about a 70% magnification UPC, way too small to pass the GS1 Gen Spec and probably too small for most commercial scanners to resolve. QR Code, like most other matrix or 2D symbologies, is supposed to be square, or at very least have square elements. This is one is badly distorted in the vertical dimension. Interestingly this mailing, from my state driver s license bureau, contains a second QR Code, and it is a near perfect and undistorted symbol. Barcodes

17 Our local farm supply store ran these ads in their latest sales flyer. Not sure what the point was, except maybe to make them look high tech. The following week they ran this one. It didn t work any better (as a barcode) than the first one (above). I wonder if it worked any better as an ad? The pet store planned to sell cases of cat food using this barcode, which was supposed to make checkout more efficient. Instead they had to break the case open and scan the 24 cans. It was not more efficient. 14 Barcodes 201

18 Here s another one of those PDF417-esque symbols. What is this thing? The oil change place does not scan these so what is it for? This is our favorite one, not because it is a bad barcode. As a matter of fact it is a great barcode from a print quality and data structure standpoint. There is nothing wrong with it except the fact that stores have not converted to imager scanners and therefore cannot scan it. This is one of the biggest misfires in retail scanning. Please comment and upload your own worst barcode blooper candidates to Barcodes

19 BARCODE VALIDATION THE NEWEST BARCODE QUALITY ATTRIBUTE When barcode technology was first launched, the concept of barcode quality was limited only to print quality of the symbol. In the ensuing years barcode data structure also became an important attribute of barcode quality. Barcode validation is now becoming the newest barcode quality attribute. What precisely is barcode validation? It means different things to different people. To some, it means making sure the encoded data represents a bona fide look-up item in a database. To distinguish it from other forms of barcode validation, let s call this barcode authentication. Barcode authentication assumes that print quality is not a factor since it is usually done with a scanner, although we know of ISO compliant barcode verifiers that are capable of also performing barcode authentication. The other form of barcode validation is sometimes called barcode matching or what we refer to as code match. This is a way of using the barcode to test whether the item or package belongs where it is or where it is going, for example an inner carton, a master carton or a pallet. In these instances, print quality and barcode authentication are assumed not to be factors. These two forms of barcode validation what we are calling barcode authentication and code match are two new barcode quality attributes that have rapidly gained importance in food and drug safety and supply chain security. For example, medical device shipments must accurately include just the right items both in type and 16 Barcodes 201

20 quantity. Code match is the most efficient way to assure that only the right items are packaged for shipment, and in the correct quantity. If an incorrect item is found in the package at destination, did it infiltrate the shipment at some way-point? If an incorrect number of valid items are discovered in the shipment at destination, was something added or taken from the shipment at some way-point? Has the supply chain been infiltrated? Code match is a relatively recent barcode quality attribute because the risk factors and consequences are so considerable. This will increase as barcodes are adopted into more--and more mission-critical--applications. Code match is relatively easily accomplished on automated packaging lines, but what about smaller, smaller volume and higher change rate packagers? The agility they require in code match set-up and testing is best done with PDT s and other small handheld devices equipped with special code match software. Is barcode validation really a barcode quality attribute? ISO verification of barcodes is testing the tool (barcode) to make sure it does what is supposed to do. Barcode authentication is making sure you are using the right tool; code match is making sure the right tool goes in the toolbox (shipment). Technically these are not barcode quality or performance attributes. In fact a barcode that passes the ISO barcode verification tests with flying colors and scans perfectly could be a substantial liability Barcodes

21 if it fails the barcode validation parameters. Ironically it would be a better problem if it failed to scan. But barcode validation is very important in ensuring the integrity of a supply chain, inventory system and other ways in which the presence of a barcode can be very useful. There are other barcode validation attributes that could be important but are not tested in any of these protocols including ISO barcode verification. One of them is symbology or barcode type. For example the barcode might pass all ISO verification parameters and both barcode validation types but be the wrong symbology. If the use-system is expecting Code 128 but the presenting symbology is Code 39, the user system could fail. 18 Barcodes 201

22 ABOUT THE AUTHOR John Nachtrieb is a nationally recognized barcode expert, and was a co-founder and CEO of Fotel, Inc., the pioneer of film master manufacture and the firm that created the film master for the first commercially scanned barcode in the US. This direct experience gave him the lead in understanding both the potential of this new tool and the necessity for barcode quality. John s focus for nearly 40 years has been to serve the customer well by championing the Bar Code quality mandate. Click here for a list of his current and past clients. His impeccable service begins with a comprehensive knowledge of the industry, listening carefully and asking the right questions to understand clearly the customer s situation and concerns, and only then proposing a solution to the customer that makes sense for their business. These solutions may take one or more of the following forms: It s Not About You, It s About Bacon 19

23 Specific Problem Solving Securing and installing the right equipment for the task at hand Providing education to the organization through several venues This approach has made Barcode-Test a formidable competitor in an industry becoming preoccupied with price over value. In the 21st Century bar code systems have become ubiquitous; supply chain globalization and product safety issues have made precise barcode quality mandatory. Barcodes are part of the larger Automatic Identification and Data Capture (AIDC) technology, which continues to evolve. There is a long and bright future for barcodes as their unique attributes are better understood and appropriately implemented along with other AIDC technologies. Helping users understand the technology mix is the most valuable service a barcode expert company can provide. Our goal is to assist product manufacturers, package printers and suppliers in managing barcode related risk and support reliable, predictable barcode integrity. John was degreed at DePauw University and has a Certification in Business Administration from the University of Illinois. His other certifications and endorsements include: 20 About The Author & Book Credits

24 GS1 US AIDC (Automatic Identification and Data Capture) Certification, 2012 Presenter, Barcode 101 Seminar on Barcode Quality and Compliance, 1990 to present Presenter on Barcode Quality in Value Cards, International Card Manufacturing Association Trade Show, 2009 Member, International Association of Packaging Professionals (Chicago Chapter) Member, Technical Association of the Pulp and Paper Industry (Chicago Chapter) Seminar presenter, 2012 AIDC Institute at Ohio University. CONTACTS John Nachtrieb, Author Barcode-Test, LLC Resources It s Not About You, It s About Bacon 21