Free Your Data

Once, data were trapped in horizontal, between-manufacturing-systems passages on the factory floor—and business managers longed for the information to be freed. Visionaries prophesied such vertical data transport. Some suggested this could be done with few glitches. Others more realistically suggested that tweaking and gee-whiz software packages were needed. Skeptics, as usual, cast doubts.

But the prophecies proved accurate. In-service combinations of device and software technologies now demonstrate successful, performance-motivated factory floor-to-business platform linkages. They’re made unobtrusively, and they don’t affect control platforms.

Hardware components used in such linkages may be Ethernet-enabled input/output (I/O) modules, for example, or vision devices with built-in device servers. To get shop-floor data to central control spaces, these technologies can be connected around or through traditional control platforms. Device data goes to manufacturing execution systems (MESs) or enterprise resource planning (ERP) systems.

软件衔接device-to-enterprise空间will likely develop faster connections. It may have pre-configured data links and give users significantly reduced integration times. Troubleshooting may get easier for users and systems integrators, thus decreasing profit-robbing downtime.

For certain, the appropriate device and software combination helps manufacturers analyze production data, and will create genuine user-friendliness. That same apparatus and software mix can also help manufacturers improve floor-level, horizontal communications between, for example, programmable logic controllers (PLCs), human-machine interfaces (HMIs), bar-code scanners and even display panels. And the right choice and blend of technologies also means vertical communications between manufacturing and enterprise systems are value-adds to the enterprise.

Key foundations to linking that bottom-to-top interval are Ethernet-ready devices. While not a complete list, some providers of those enabled I/O modules include Acromag, Advantech, National Instruments, Omron, Opto 22, Phoenix Contact, Sixnet and Wago. Ethernet-ready vision-device suppliers include Cognex, DVT, Omron and Rockwell Automation, among others.

有了这样一个视觉设备,用户发送数据到plcand then to the enterprise, says Carl Gerst, the ID program manager within Natick, Mass.-based Cognex’s Machine Vision Systems Division. But some manufacturers aren’t yet fully aware of that possibility. “You go into any automotive plant—transmission, brake, axle assembly, you name it—and because the parts are cast steel, they haven’t been using (identification) technology to track their products.”

Companies using the tracking technology, however, do so because they want to better understand quality. Using a bar code called DataMatrix, in a process called direct part marking, two-dimensional bar codes are placed on individual parts. Once that’s done, Gerst says, users may place ID readers at every point on the line, where value is added to the component.

DVT’s Internet-ready cameras, which have ModBus and eXtensible Markup Language capabilities, support shop floor and enterprise communications. One is the inspection level to personal computer- and PLC-based controls, says Applied Engineering Manager Phillip Heil, located at the company’s Duluth, Ga., headquarters. “The second is working with MES or ERP systems.”

Wago’s Ethernet programmable fieldbus controller fits within the Wago I/O rack and communicates with 10/100 megabit per second Ethernet. It supports Internet technologies such as file transfer protocol, making data available to the enterprise, says Mark DeCramer, Wago’s advanced electronics manager at the company’s North American headquarters in Germantown, Wis. Other benefits include integration of legacy equipment and diagnostic and production data acquisition.

Software bridges

Some available software packages can link devices horizontally or vertically within the enterprise. One is Louisville, Ky.-based I/Gear’s data-transport unit or DTU package. The other is Minnetonka, Minn.-based Digi International’s device server. Both solutions have external hardware boxes.

Digi’s solution finds use in oil and gas, consumer goods, pulp and paper, automotive, semiconductor and general manufacturing industries, says Mike Finley, of Dallas-based Industrial Networking Solutions. Besides being used where legacy PLCs are not Ethernet-ready, other places the Digi device server are applied include flow computers, barcode readers, scales, text-messaging displays or any serial-based device.

Better performance drives use. “When you look at why you want to connect into a network, it’s generally to judge the health of the overall environment. The key is to get a simultaneous view of many different pieces of data,” says Joel Young, Digi’s vice president of engineering. However, until now, most manufacturers appear to have addressed connectivity through point systems by writing custom code or having it written, or by purchasing software interfaces.

“One-to-one connectivity approaches often led to the proliferation of custom and packaged data-transport systems that are expensive to create and difficult to maintain,” says Robert Toole, I/Gear’s software products manager.

A vendor-neutral communications platform apparently overcomes those challenges, by using open standards to gather data into a single source. “Instead of writing custom codes to connect to ERP, I/Gear has the interfaces built into it,” adds Toole. That allows users to utilize standard, off-the-shelf technologies.

Advanced Production Systems (APS), a Louisville, Ky.-based systems-integration company that has been in the MES environment for about 10 years, applies I/Gear software in turnkey implementations, says President Don Korfhage. Time and customer complaints are reduced with a turnkey solution, he says, because, with custom code, usually only one programmer knows what’s been input into any particular package. Now, users can now make minor changes and troubleshoot. “Being freed from custom code is a big issue, because downtime might cost $10,000 a minute in some manufacturing installations.”

Before APS discovered the I/Gear solution two or three years ago, Korfhage indicates, “in a lot of the sequencing and verification that we were building, we saw that, at times, a mistake could cause a transaction to be skipped, duplicated or out-of-sequence.”

Most clients have a build-to-order mindset, Korfhage says, and the software package’s functionality is useful in building-to-schedule operations. “For example, Toyota may place an order with the Dana Corp., an automotive-parts assembler. They have to make sure that production is synchronized with Dana’s schedule.”

Connecting for quality

Continuous improvement and quality assurance are precisely how the Dana Corp.’s Commercial Vehicles Systems or Heavy Truck Division, located in Henderson, Ky., uses an I/Gear-Wago I/O combination. For two years, at this plant, which assembles single- and tandem-drive axles for Class 8 trucks, such as Freightliners, the quality department had requested a bar-coded, assembly-verification system, says Information Technology Manager Tom Hatfield.

Then, in 2001, the first phase of a three-part implementation began. The second phase is now proceeding. “We’re coming from shop-floor I/O modules that feed into a Microsoft SQL database—which is like the backend. The I/O modules interface with the software package’s server, which in turn interfaces with the MS database. That same server houses the Internet home page for the database and is where the quality department will look at what’s happening on the shop floor.”

Presently, though, data don’t go higher in the enterprise, Hatfield says. “But our goal is to connect to higher levels in the enterprise by the end of 2004. We’re investigating an Oracle transaction with the software package. That would be part of an ERP system, an inventory back-flush or parts-consumption transaction.”

With respect to MES connections, “as assemblies go down the line, their pass/fail information is written back to an MES system that can be used by upper management to see what’s going on, on the shop floor,” says Sean Pardue, an APS applications engineer involved in the installation of the hardware-software technologies at Dana’s Henderson plant.

It’s an Internet application, somewhat like a digital dashboard, he says. “It applies to that concept, where you have all the assets on the line and you can drill down from the top of the enterprise to see what’s happening on the line.”

The device-software combination like that at Dana is used as a non-intrusive approach to gather this strategic information, Korfhage says. “The Wago device allows us to drop I/O strategically in areas without interrupting the control system,” he adds. APS has deployed the modular software solution on the plant’s six assembly lines, Pardue says.

See sidebar to this article: Electricity charges I/O connection