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Open-architecture CNC continues advancing

Chalmers, Raymond E

As the worldwide market for CNC grows

Not only is the market for computer numerical control (CNC) hardware, software, and services continuing to grow, it is experiencing significant shifts. According to "CNC Worldwide Outlook," a recently updated study from ARC Advisory Group (Dedham, MA), the worldwide CNC market exceeded $3.7 billion in 2000 and will exceed $5 billion in 2005.

"A market once dominated by Fanuc has now seen one of the most significant shifts in the last 15 years," says Sal Spada, senior analyst at ARC. Marking this shift are acquisitions, joint ventures, and mergers, making the CNC market no safe haven for suppliers offering a simple commodity solution. "After this period of consolidation is over, the only survivors will be niche market players and global suppliers," Spada says. "Price competition in the machine tool metalcutting and fabrication sector will continue to seek lowest-cost solutions that will allow many specialty CNC suppliers to coexist in this market. "

One technology partnership announced in May is advancing the cause of open-architecture CNC, defined as an unbundled software application (i.e., not tied into proprietary motion-control hardware) that provides unconstrained access to all data items within the control, and leverages commercially available PC hardware. Manufacturing Data Systems Inc. (MDSI, Ann Arbor, MI) announced a multiyear product development and license agreement with Hurco Companies, Inc. (Indianapolis, IN), which makes milling machines, turning centers, press brakes, and tooling, as well as control software, computerized machine systems, and industrial automation products.

The multiyear agreement consists of a development agreement and a software license agreement. Under the development agreement, Hurco will integrate MDSI's OpenCNC software as a core technology component onto its own next-generation patented openarchitecture software system. The multiyear software license allows Hurco to use MDSI's OpenCNC software on the company's SmartNet product line.

MDSI's OpenCNC product, in production since 1993, is an unbundled, open-architecture, all-software CNC that runs on Windows NT, providing a common control technology across a range of machine tool types, including single and dual-turret lathes, single- and multiple-spindle milling machines, grinding equipment, gear hobs, gantry machines, and dial index machines. The software has a three-tier architecture that isolates high-priority machine-control tasks such as trajectory planning from toolpath preparation tasks and user-interface tasks. All three layers, though, share a single, real-time database that OpenCNC dynamically configures for maximum machine functionality for a given set of tasks. As opposed to proprietary hardware-based CNCs that can require multiple processors, OpenCNC's advanced scheduling and control algorithms use only a fraction of a single Intel processor, allowing other applications to run at the machine tool on the same chip.

Moreover, the open, real-time database provides an important gateway for collecting and distributing realtime manufacturing data and rapidly integrating thirdparty applications. Called Significant Events in OpenCNC, it allows gathering production, maintenance, or quality data directly from the machine tool without operator intervention or specialty hardware. Such critical data can then be imported into a company's chosen manufacturing execution system/ materials requirements planning (MES/MRP) software. It can do this because it supports Microsoft's object-oriented standards in Windows, including Windows DNA (Distributed Internet Applications) for Manufacturing, and OLE/OPC (Object Linking and Embedding for Process Control). Realtime data technology in OpenCNC software will be combined with Hurco's patented real-time object-oriented software to provide manufacturers not only the ability to use high-performance machining, but also to gather and broadcast machine data throughout the manufacturing enterprise via the Internet. Access to machine data that can be pushed across a factory intranet or the Internet gives Hurco the opportunity to offer additional services such as online support, online engineering, and remote machine and process diagnostics to its customers.

Open-architecture CNC also is making advances at the device level. Earlier this year, MDSI announced it has created a new digital device driver for OpenCNC software to support the Yaskawa Mechatrolink digital communications network. The new MDSI device driver makes it possible to support an open digital communications link to the Yaskawa family of digital servo drives, inverters, and I/O. This is the first time an independent third-party CNC company has been given access to Yaskawa's Mechatrolink interface and invited to integrate new technology. Yaskawa (Waukegan, IL) is a $3 billion global manufacturer of motors and drives.

The benefits of integrating an open-architecture, all-software CNC with a digital-device communications network system include shortened setup time, as no ribbon cable or related hardware are needed. All communications can take place with a single interface cable. Improved communications between the CNC and drives means improved device performance, whether those drives exist on a spindle, robot, or machining center. "This new device driver for Yaskawa also gives MDSI access to drive technology available from one of the most dominant suppliers in the world," says ARC's Spada.

"For Yaskawa, this relationship ratifies our own approach to open architecture," says Dennis Kostrzewski, Yaskawa senior manager. "Our drive products have been 100% digital for some time, but the full advantages were only available with our own general motion and digital network solution. Having an interface into an open digital CNC software helps MDSI and Yaskawa customers realize all the performance characteristics already built into our products. There's no need for any D/A interface on the servo side."

The first people who benefit are the machine-tool builders, Kostrzewski continues. The most immediate benefits are reduction of internal wiring and the ability to gain diagnostics from the device. The user benefits in that the resulting machine is usually more compact, taking up less space on the floor. The machine controls system is tightly integrated for maximum performance and flexibility. Fewer connections also make the machine tool inherently more reliable, and faults become easier to identify. The MDSI/Yaskawa relationship is a significant step forward for machine controls and open-architecture CNC, "and we're focusing on actual motion and machine performance, and anything that improves those properties," Kostrzewski says. While Yaskawa offers a wide selection of servos, inverters, and I/O for a complete solution, an MDSI customer can choose from more than one vendor, mixing Mechatrolink devices and DeviceNet I/O for best advantage, in keeping with the definition of open architecture.

MDSI sees the relationship with Yaskawa as advancing the cause of open-architecture CNC. "It's no longer a question of open architecture becoming the standard of choice, it's how long will it take to achieve dominance," says MDSI president and CEO Jim Fall.

This isn't the first time MDSI has interfaced OpenCNC with a device driver. Last year, the company developed an interface in collaboration with Rexroth Indramat (Lohr, Germany) and its SERCOS (Serial Real-Time Communications System) network for communicating with Rexroth servo drives and controllers. As in the Yaskawa relationship, the SERCOS interface allows controlling and monitoring servo drives from a single PC with one fiber-optic cable and a passive communication card between the PC and the drive.

Validating the rational design of the MDSI CNC software is the fact that it took less than a month to integrate OpenCNC with the Yaskawa Mechatrolink digital communications network.

Manufacturing engineers, as opposed to controls engineers, are the real beneficiaries of CNC improvements. "Even with an economic slowdown and reductions in spending, people are still looking at means of streamlining production," says MDSI's Fall. "The need for continuous improvement is even stronger today than it was 10 years ago, and manufacturing engineers are challenged constantly on this point. Open-architecture CNC provides a real tool to do this. The possibility of regularly using remote diagnostics, which MDSI's OpenCNC makes possible, goes beyond how to monitor and fix a single machine. It makes it possible to fix a broken process. The data points the way to fixing a process before it's seriously broken."

Copyright Society of Manufacturing Engineers Jul 2001
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