• use barcode readers in an automated work cell, more...
• terms & terminology of barcode readers
• contact for further information

PAA guide to barcoding: Download app note: Barcoding (LA256)
Barcoding as part of a system: Download app note: System Integration (LA223)
Full glossary of terms: http://www.tharo.com/glossary.htm
Specification organizations: http://www.tharo.com/barinfo.htm
Warehouse terms: http://www.dataid.com/wrhseglossery.htm
general barcode information: www.bambooweb.com
general barcode information: www.barcodeisland.com
general barcode information: www.barcodefaq.com

Process Analysis & Automation supplies a range of software products, hardware products and completely integrated laboratory automation systems. OVERLORD features support for the general barcode readers such as serial port and keyboard wedge as well as specialized products from Symbol and Keyence.

Process Analysis & Automation offers a wide range of the available barcode reading systems for integration into an automated workcell. Using our integration software packages, Overlord2 dynamic scheduler and OVERLORD Scheduler, each device can be integrated into a complete automated system with the users choice of robot. Advice on which scheduler type to choose. More...

Each device can be integrated into a complete automated system with the users choice of laboratory robot and ancillary equipment.

The pipetting robot is a key part of an automated system, and the selection of the correct robot for the system is very important. For advice on system integration please go to system integration or Download System Integration application note (LA223).

Barcodes are used in the OVERLORD environment for plate tracking, usually to match different plates during plate-to-plate transfers, and to match plates to the data file from a plate reader. Plate barcodes are read by passing the plate in front of a barcode reader and storing the resultant label as a string variable. This can be used in filenames or identification strings in data files. Download our document on barcoding, download Barcoding application note (LA256) or the more detailed section on barcode readers.

CCDIs the cheaper technology; some people are really impressed by their performance, our impression is they are good as handhelds but not so good in an automated workcell.

Linear barcodes are a series of black and white lines in a linear pattern. The different patterns are indicative of the information that is represented and usually has a human readable information strip under the linear pattern. Different patterns (or symbologies) can represent the digits 0-9 only or the complete alphanumeric sequence available on a PC, i.e. ASCII 0-255. The more data that each character has to hold, the wider the actual barcode is to represent the data.

Each character is represented by a series of bars, separated by a blank space (the intercharacter space), there is a start character and a stop character (so the barcode reader know from which end to start) and a quiet zone at each end. Failure to read a barcode can sometimes be caused by the barcode extending to the edge of the label, and the edge of the label looks like a fine bar under certain lighting conditions, confusing the barcode reader with an unexpected bar.

Discrete Symbology is where all characters are encoded in the symbol may be interpreted individually without respect to the rest of the barcode. Such symbologies have characters that both start and end with a bar. Individual characters are separated by some amount of inter-character spacing. The intercharacter spacing carries no information other than to separate the characters.

Continuous Symbology is one in which the individual characters of the symbology cannot be interpreted by themselves. This is because the characters start with a bar and end with a space. The final space is "terminated" by the starting bar of the next character. A character cannot be taken individually as there is no way to know how wide the last space is without knowing where the next character begins. Continuous symbologies normally implement some kind of special termination bar or termination sequence such that the termination bar terminates the last space of the last data character.

Two-Width Symbology has spaces and bars that are either wide or narrow. This has the benefit of simplicity-once it is determine how wide a "narrow" bar or space is, anything over a certain width can be considered "wide." This allows for a large level of print tolerance in lower-quality printing conditions.

Multiple-Width symbology is where the bars and spaces that may be of 3 or more widths. The narrowest bar or space may be X in width, a medium-width space or bar may be 2X in width, and a wide bar may be 3X in width. Since there are more possible combinations available in a multiple-width symbology, data encoding is often more efficient and results in a tighter barcode. Multiple-width symbologies are usually continuous symbologies.

Fixed-Length Symbology is where an exact number of characters or digits are encoded. For example, a UPC-A barcode always encodes 12 digits of data. An application may not encode less or more than the pre-defined fixed-length of 12 characters. The symbology itself defines the length of data.

Variable-Length Symbology is where the code can carry a message of any length. For example, Code 128 may encode any number of characters that can reasonably fit physically in the printed barcode. The symbology itself does not define how many characters of data must be encoded.

Self-Checking Symbologyis where a single printing or scanning error will not cause one of the component characters to be converted erroneously into another valid character.

Paper
You can print a barcode on anything, but you can’t necessarily read it afterwards ! The better the quality the paper, the better the read likelihood. The best label stock for laboratories is polyester.

Printers
There are several types: Dot matrix, I would forget this option; Laser printer, generally good quality but not very laboratory proof; thermal transfer printer, specialist printers that emboss a layer of carbon from a ribbon on the label, these are the best.

Software
There are fonts that you can print from Microsoft Excel or Microsoft Word, there are specialist packages that you can purchase that allow control of all the facilities on a sophisticated barcode printer. The choice is down to what quality of printout you require, what information you want on the label and how long/what atmospheric conditions the label has to survive. The costs go from freeware to many hundreds of £/$.

There are over 30 different barcode formats. These have names like: Code 39, Extended Code 39, Code 128 (with character set selections Auto, A, B and C), UCC/EAN-128, USS-128, Interleaved 2 of 5, Codabar, UPC-A, UPC-E, MSI, EAN-8, EAN-13, Code 11, Code 93, Industrial 2 of 5, PLANET and POSTNET.