Hewlett Packard Co.
Â It’s called the HP Open Architecture Controller; it is a computer numerical control (CNC) system for machine tools, and yes, it is from Hewlett-Packard (Palo Alto, CA). Specifically, it comes out of the HP Test and Measurement Organization, which is, interestingly enough, the original business unit of HP.
Remarks HP’s Peter Mills, “What we think we bring to the table is considerable experience in motion control for high-performance servo systems.” By which he means systems, for example, that are used in semiconductor manufacturing. But what does that have to do with metalcutting machine tool control for applications in automotive and aerospace, two of the target markets that HP has identified for the new CNC controller? Plenty, according to Mills, the marketing manager of the controller through HP’s Santa Clara Div. That is, he explains that the semiconductor wafer stepper machine costs on the order of $1-million. It runs 24 hours per day, seven days per week. And within four years it is obsolete. During the processing of the wafers, the piece parts can be valued at $500,000 each, so there is zero tolerance for misalignment. What this means is that the HP servo boards that are used to keep these things going have to have high reliability, excellent uptime and precision. Things that are certainly key to metalcutting operations. (HP people do have a solid familiarity vis-Ã -vis metal cutting applications, given the company’s laser-based machine tool calibration equipment.)
The second thing that HP brings to the table is the company’s vast know-how in the area of open systems for computing (i.e., according to the company, it is the world’s leading supplier of open UNIX system computers). And openness is the key to this development.
What “Open” Means
Nowadays, “openness” with regard to CNC controls is the characteristic to have, it seems. However, the HP argument regarding what “open” means puts that company in a different position from many other vendors. As Mills explains, the traditional vendors of CNC units developed their own real-time operating systems, high-speed buses, CPU boards, drive interfaces, and input/output (I/O) methods. The key terms here are “their own.” Which means proprietary.
These vendors, Mills continues, are now offering what they are calling “open” or “PC-based” CNCs. But he says this is more show than go: the CNC with a PC is “open” only to the extent of the operator interface, the front end of the system. The other aspects of the traditional CNCs, he maintains, continue to be proprietary.
The HP Open Architecture Controller is fully open to the extent that it is based on industry standard hardware, software, as in Intel microprocessors, Windows NT, LynxOS, DeviceNet distributed I/O, and SERCOS fiber-optic bus. Getting to the motion-control software for customization is critical, Mills says, for machine tool builders and machine tool users alike to be able to customize and modify the performance of the CNC. But this, apparently, is an area that has tended to be off-limits. However, the HP unit uses modular, message-based motion-control software. Modules communicate via standard message formats known as application programming interfaces (APIs). HP provides documentation defining the APIs. What’s more, the company actually offers developer’s kits that are specifically for modifying the motion-control software. “Change the kinematics if you want, or the acceleration profiles. Integrate force or acoustic sensors. We’ll provide the tools to make the modifications and to integrate sensor data on a real-time basis. When we say `open,’ we mean fully `open,'” Mills says.
There are two main elements to the HP Open Architecture Controller. One is the operator console. It implements a Pentium-based industrial computer that runs Windows NT 4.0; it provides networking and multitasking, access to CAD drawings, shop floor control programs, e-mail, or what have you. The operator console also includes a DeviceNet board for the interface to the machine I/O. The other element is the motion chassis. It features an identical Pentium-based unit. However, it runs LynxOS, which is a real-time operating system that allows third-party integration and uses industry standard development tools. It is a POSIX-compliant operating system. The operator interface and the CNC motion system are linked with Ethernet.
So what does this mean? According to Mills, what it really means is that users can save money in operation because what standards allow is the ability to make changes and modifications without having to have lots of customization which has been the case with standard CNC systems. The upfront costs might be higher for the HP system than the conventional CNC, he admitsâthe HP unit costs from $30,000 to $40,000âbut the “cost of ownership,” he maintains, can be decidedly lower compared with a proprietary system. For example, he references computer memory. He says that to buy it from a proprietary CNC vendor, it can cost from $3,000 to $5,000, whereas the same amount of memory can be purchased from HP for $500. He explains that the disparity is simple: the proprietary vendor wants to make money on options and upgrades. “If our price is too high, the person can go to the local computer store or check out a computer magazine and buy it. Our hardware is commercially available. If you have to buy an Ethernet board from one source and not from anyone else, then that one source is less willing to make you a really great deal,” he says.
“In the computer world, the way you excel is by embracing more standards than the other guy so that you can talk to more printers or interface to more networks or browsers and so on. The more standards you embrace, the better buy you become. But in the CNC business, vendors have excelled by rejecting standards. They say they are better because they are different. They have different solutions for I/O and buses, and drive interfaces, and so on.
“We’re hoping that the criterion for success in the CNC business will become who embraces the most standards,” Mills says.