Colyton Industrial Marking Solutions
design and manufacture custom marking solutions for industrial marking requirements We work with ID-Integration Inc. in the US to provide a comprehensive solution to your UID marking problems.Traceability
Data Matrix Codes
Direct part marking generally uses codes to compact the size of the data being stored, often combined with a limited amount of human readable information. 1D and 2D codes allow large amounts of information to be stored in a given amount of space, 2D codes having higher densities and generally more secure than 1D codes. The availablity of low cost 1D readers maintains their use in direct part marking but for long term readability of information the 2D code is the best solution.
The Data Matrix code provides a means of storing large quantitiesof data, securely in a small physical size, as the code provides a large degree of redundancy allowing data to be recovered even from badly damaged codes. The Data Matrix is especially good for very small codes, due to the code's ability to store fifty characters in a symbol that is readable at at 2 or 3 mm2 and the fact that the code can be read with only 20% contrast ratio. The data matrix code is highly scalable with commercial applications as small as 300 micrometres and as large as 1metre square.
These codes can be produced by laser or pin stamp although the pin stamp version requires specialised readers that are optimised for reading round rather than square dots. The IAQG specification deals with the quality and standards for marking 2D Data Matrix codes with pin stamp markers.
The QR code is another example of a 2D code that is acheiving popularity in the commercial markets especially in convenience-oriented applications aimed at mobile phone users (known as mobile tagging).
QR Codes
A QR Code is a 2D matrix code (or two-dimensional bar code) created by Japanese corporation Denso-Wave in 1994. The "QR" is derived from "Quick Response", as the creator intended the code to allow its contents to be decoded at high speed.
Although initially used for tracking parts in vehicle manufacturing, QR Codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (known as mobile tagging). This increased use will in turn drive down the costs of using QR codes which will generate even more use of the codes.
QR codes have the highest data capacity of the 2D codes but have a lower error recovery rate than the 2D Matrix code which has a much higher use in industry.
QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards or just about any object that users might need information about. Users with a camera phone equipped with the correct reader software can scan the image of the QR Code causing the phone's browser to launch and redirect to the programmed URL. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks.
Users can also generate and print their own QR Code for others to scan and use by visiting one of several free QR Code generating sites. The QRcode shown on the right of this page is a link to the home page of this site and can be read using a mobile phone with the correct software.
QR Code is an open format - the format's specification is available royalty-free from its owner, who has promised not to exert patent rights on it. The term QR Code itself is a registered trademark of Denso Wave Incorporated.
Unique IDentification
The U.S. Department of Defense has instituted a mandatory program to uniquely identify property, equipment, materials and supplies. The Unique IDentification (UID) Program is mandatory for all DoD solicitations issued on or after January 1, 2004 for items that:
* Cost over $5,000
* Serially managed
* Mission essential
* Controlled inventory
* Consumable item or material where permanent identification is necessary
UID is an asset identifier that is globally unique and unambiguous and ensures data integrity and quality throughout life.
The Technology
The technology used to support UID is the two dimensional "barcode" such as Data Matrix ECC 200, PDF417 or other approved 2D codes. The Data Matrix code, for example, can store up to about 2000 characters, so it can contain 100 times the data of a linear barcode of the same size. It can be read from any direction, can supply accurate data even if damaged and can be easily scaled up or down to fit the application space.
Reading Marks
In order to produce traceability records it is necessary to read the marks which can be done with vision systems that can both read and verify the quality of the marks using cctv camera technologies with specialist software or by means of specially developed readers including versions based on ultrasonic techniques. In general 2D codes are preferred although 1D barcodes still have many applications due to the higher cost of 2D readers, in part due to the higher volumes of barcode readers produced by manufacturers.
These readers can be hand held or fixed in position and with 2D codes large quantities of information can be stored in the codes which can be read in the same time as the simpler barcode.
This information can then be stored into databases that can be accessed from web applications making the data widely available across the world.
Recording Data
In order to provide complete traceability it is best to record the data that is to be marked at the marking stage and to read back the data and verify and validate the mark, again recording this information at the beginning of the process. Once the data has been stored then the marks can be read at any time and additional data added to the recorded data to allow the history of the component or assembly throughout its lifetime.
CI Marking Solutions have many years experience in working with these technologies and the provision of custom database driven software packages including systems based on web technologies. Recording the reflectivity of the material can be used to check for changes in material specification or degredation of the lighting and can assist in solving problems with the reading equipment.
The use of direct part marking throughout the production process, identifying the machines used in the manufacturing process for example can then be used at a later date to control how a company deals with problems in a finished product. By checking which machines were used in producing a series of components that have failed can allow manufacturers to limit the number of finished parts that need to be recalled or replaced, dramatically reducing warranty costs.
In addition to monitoring a component, 2D readers can also be used to monitor the marking unit itself, recording the results of validating a mark over a period of time allows trends to be established, and pin wear to be monitored. As a pin wears the mark it produces becomes bigger as the end of the pin flattens, the dot size can be monitored over time and used to determine when a pin needs to be changed.