Equipment 101: Data capture basics
Voice technology is often applied to labor-intensive activities, like piece picking, putaway, replenishment and cycle counting.
October 01, 2011 - MMH Editorial
BAR CODE SCANNING
Bar code scanning is the most common way to collect data at every link in the supply chain. There are two major components and considerations in any bar code solution:
choosing the right type of bar code or bar code label for the right type of application, and
- choosing the best scanning device for the application.
Bar codes are everywhere and on everything. In fact, according to Marty Johnson, product marketing manager for Zebra Technologies, if something doesn’t have a bar code, it may not exist in an automated system. That may be a bit of an exaggeration, as RFID and other technologies gather steam. But, bar codes are certainly pervasive. And, he adds, the ramifications of not having some method of identification are huge and costly.
Bar codes can have different appearances and can have different levels of data storage capabilities. In today’s industrial settings, there are at least three types of labels.
1. 1D, or linear, bar codes are the most familiar arrangement of black and white lines and spaces used to create the Universal Product Code (UPC). This is the bar code that people think of first, says Johnson. It’s the linear style style—a classic UPC with stripes of varying degrees of width.
2. 2D bar codes come in a variety of forms, but consistent across the board is that all information is encoded vertically and horizontally. “A 2D bar code has a different look to it,” explains Johnson. “It’s basically two dimensional and looks like a series of blocks and triangle and squares in varying patterns.”
The 2D type can be used when there’s a need to store more information than the 1D UPC style can handle. A 2D bar code can hold a different level of detail, and according to Johnson “is more in tune with mobile applications.” Rather using a traditional scanner to collect data, a smart phone can take a physical image of it and capture the information that way.
3. Direct part marking is used to apply a unique identifier directly to a part that can be used in the future for tracking and tracing. The importance of direct part marking for tracking and tracing comes into play in an open-loop supply chain in many ways, including safety as it relates to a food or pharmaceutical product recall or in the case of a part being part of a larger finished product, like an airplane or a car. In the retail apparel setting, direct part marking is being applied to clothing labels. Suppliers are tagging individual items, which enables better inventory control and helps avoid stock out situations for retailers at the consumer level.
Techniques used to apply the identifying data include ink spraying or etching directly into a part.
For example, polyester can resist damage caused by contact or exposure to chemicals and can be stored outdoors for about two years; polyimide can tolerate temperatures up to 500 degrees; polypropylene can also tolerate high temperatures and be stored outdoors for between one and two years.
The cost of a label depends on its size, material and volume needed.
After choosing the right type of bar code, the next step is to choose the right type of scanner for capturing the data stored on the bar code.
Laser scanners, which read 1D bar codes, are the most common type. These devices read bar codes in conjunction with an oscillating mirror that automatically moves the beam back and forth across the bar code.
Imaging technology can also read 2D bar codes and direct part markings. These systems capture the image of the bar code all at once, much like a digital camera. The imaging technology automatically frames the information on the bar code and pulls it in. The data capture is extremely fast, with imaging technology response time measured in sub-seconds. “This technology can push information out to the workforce and gather it back in real time,” says Intermec’s Stubbs.
One benefit of imaging technology, Stubbs explains, is that because a camera can capture the image of any product or process and upload it in real time, it can “see” problems like the condition of a load, for example.
Regardless of the scanning technology, bar code scanning equipment options include handheld and fixed devices.
Fixed scanning devices, which are 100% automated and scan without human intervention, are commonly used as part of a conveyor system. These scanners read the bar codes on cartons as they are inducted into the conveyor or sortation system or before they are stored in an automated storage and retrieval system (AS/RS).
Fixed scanners can also be mounted at choke points in a facility, including dock doors. “Fixed scanners mounted at portals track everything that goes through a critical point,” explains Chris Warner, senior product marketing manager for Motorola Solutions.
In some operations, on-demand handheld readers are used to go out and do manual tracking, Warner says. Today’s handheld readers are lighter than their predecessors and include a litany of ergonomic improvements including hands-free features.
In some styles, handheld technology literally puts the information at an operator’s fingertips. Wearable devices like ring scanners, for example, enable true hands-free activity and leave a worker’s hands free to perform a task. Today’s wearable devices have increased processing power and more memory so in addition to reading bar codes, some can actually display full color images on the screen. This feature visually can ensure accuracy during the picking process or even while building a pallet.
There are two types of handheld readers—one industrial type and a smaller, lighter type that’s more appropriate in a commercial setting for sales force applications. “You wouldn’t want to put a heavy device on the sales floor for an associate who had to use it for a long time,” Warner says.
In all cases, once the bar code is scanned or the image is captured, software is then used to decode the data.