While PC/CNC convergence began several years ago with the PC primarily supporting the HMI (Human Machine Interface), today's controller architectures bond CNC and PC more closely together. More controls suppliers are combining standard PC tools with CNC components to exploit the power of the Web, PC-platforms, and Windows CE/NT to help engineers reduce non-productive machine time, automate tool and part changes, simplify development, and integrate machine tools with factory networks.
"Rapid adoption of Windows-based HMI is helping engineers integrate machine tools with enterprise applications and is becoming a dominant driver in improving production efficiency," explains Sal Spada, author of Machine Tool Automation Strategies, a new study from ARC Advisory Group (Dedham, MA). "Consequently, the typical life cycle of CNCs is under three years today and falling."
For example, just a couple of years after its Model A Series 160i/ 180i/ 210i CNC introduction, GE Fanuc Automation North America Inc. (Whitehall, PA), showed its Model B Series expansion at the Eastec 2001 manufacturing exposition. "Model B gives machine builders the option for more functions on a wider variety of machine types," says Jeff Kao, VP of the CNC and laser business for GE Fanuc.
"It's one of the few to offer a Windows CE operating system," explains Bill Griffith, CNC Product Manager at GE Fanuc (Charlottesville, Va). "CE is gaining acceptance because it eliminates the need for a hard-disk drive, a common mode of failure on PC-based CNCs."
Likewise at Eastec, Siemens (Elk Grove Village, IL) presented the SINUMERIK 840Di series control. Combining technology from Siemens and Yaskawa, the 840Di control will be used by the Iruma, Japan-based 50-50 joint venture, Yaskawa-Siemens Numerical Control (YSNC) to focus on gaining market share in the high-end CNC market. Machine tool builders seeking productivity improvements with a price-competitive solution will find the 840Di extremely compelling, according to Spada. "840Di supports the most widely used operator interface standards in the industry, Siemens and Fanuc, and combines Yaskawa's advanced servo design with innovative contouring software to achieve speeds that were never considered possible. Matsura, for example, demonstrated contouring speeds exceeding 1,500 inches/min at the JIMTOFF show last November," Spada says, "These are speeds that were never considered realizable in present day controllers, which are typically capable of only 300 inches/min."
Fanuc controls 31% of the market share of CNC system suppliers according to the ARC study. Siemens follows at a distant second with 16%, followed by Mitsubishi with 8.9%, Indramat with 4.8%, and Heidenhain with 4.1%. While Rockwell Automation controls only 1.4% of the market, it's one of the few using the Microsoft conventions for its CNC API (Application Programming Interface). "Rockwell is not a big player," says Spada, "but it's one of the few focused on OPC [Object Linking or Embedding for Process Control] connectivity, which to me was a big move on their part."
While Rockwell didn't exhibit at this year's Eastec show, the company introduced the Allen-Bradley 9/PC, a PC-based CNC offering open interfaces for servo, part programming, communication, HMI, logic, and I/O at IMTS 2000. "A lot of effort went into developing an OPC-based data server, a standard structure for passing data back and forth between PC and CNC environments," ex-plains Mark Devonshire, Allen-Bradley CNC marketing manager, Rockwell Automation. "The 9/PC's OPC-compliant API gives us the best opportunity, in general, to interface seamlessly to third party software without having to write some interface code in between."
In fact, Machine Control Technology Inc. (Williams-town, MI) was on hand at IMTS showing its 9/PC-based MCT Open HMI. The customizable HMI uses PC technology to provide production management enhancements, controls engineering support, and maintenance benefits, according to MCT President Jay Merkle. "OEMs can build all relevant information into the machine, and develop advanced operator interface features without being proficient in Visual Basic programming," Merkle says.
OEMs and integrators, such as MCT, are realizing productivity gains during development and integration with easy-to-use customization tools. Open interfaces such as OPC assist in data exchange between system applications and the outside world. And object libraries accelerate HMI customization with third-party applications. For end users, modular and open controls can provide HMI with a more common look and feel throughout the plant. It also helps manufacturing and controls engineers integrate machines with production management systems, business information systems, and other machines.