RVSI Unit Introduces a Verification System for Data Matrix Codes

Robotic Vision Systems Inc.'s (RVSI; Canton, MA) said its Acuity CiMatrix division introduced the DMx Verifier+, a system that allows users applying Data Matrix codes -- usually called "two dimensional bar codes" -- to verify in real time that direct parts marks or labels have been properly applied and are readable.

With prices beginning at $9,950, each DMx Verifier+ system includes an Acuity CiMatrix Visionscape 1000 intelligent frame grabber and CD-ROM-based software for reading and grading Data Matrix codes. The software can also be used in conjunction with RVSI's new MXi handheld symbology scanner. Other components are available that include camera kits, lighting and fixtures for reading Data Matrix direct part marks.

Data Matrix codes, which resemble small checkerboards, are found on an increasing number of products. Unlike one-dimensional bar codes, which can hold a relative handful of digits identifying a manufacturer and product identification numbers, a Data Matrix mark can encode a sizeable amount of alphanumeric information. Moreover, while bar codes are typically imprinted on paper labels that are then affixed to consumer goods, Data Matrix codes may be marked directly on a product either through dot peening, ink jet, laser marking, lithography, or other methods.

"Because each Data Matrix is unique to the product to which it is affixed, each code must be verified," says Bill Baker, senior VP for marketing at RVSI Acuity CiMatrix. "Marking processes go awry; objects move while being marked, laser power settings fluctuate, and dot peens drift out of alignment. Over time, the marking device can produce a mark that is no longer readable, requiring re-calibration of the marking device. The DMx Verifier+ is designed to provide the same quality of validation for direct part marks as is currently available for bar codes."

The DMx Verifier+ reads each Data Matrix code and computes a variety of mark quality measures. These include each mark's symbol contrast, axial uniformity, print growth percentage, unused error correction, cell placement errors, overall grade and overall matching. Each test describes a specific attribute of a direct part mark.

"We're going far beyond the AIM (Automatic Identification Manufacturers) specification," Baker says. "There are other verifiers available that will help a user grade a high-contrast mark on a paper label." According to Baker, the DMx Verifier+ is the only Data Matrix grading system that is capable of making repeatable and precise marking quality measurements for direct part marks.

For example, microprocessor manufacturers can inscribe codes that are barely visible to the naked eye. Medical instrument manufacturers use Data Matrix marks to code serial numbers onto curved surfaces, and NASA is investigating putting a Data Matrix code on mission-critical components used in space programs. "Our users have asked us to come up with a means of ensuring the repeatability of each Data Matrix mark; the DMx Verifier+ is the solution to that need, especially in the world of direct parts marking," says Baker.

RVSI's machine vision systems currently serve the semiconductor, electronics, automotive, pharmaceutical and packaging industries.