Linux:
Remain competitive with an open system

By Steve Schoenberg

Linux is dramatically changing the game in instrumentation and automation systems by combining the advantages of open and proprietary systems. Open systems provide interoperability and the benefits of freedom of choice in the products we select. Proprietary systems often provide performance advantages through design optimization and innovation. Linux bridges the gap between these seemingly incompatible concepts by providing a completely open template that invites innovation and then gives you a choice of sharing your creation or maintaining your enhancements as a proprietary advantage. Linux provides the means for product designers to create open systems and still maintain their competitive advantages.

By way of background, Linux is the creation of Linus Torvalds, who shared his vision of "open source" software by creating a nonproprietary version of the popular and robust Unix operating system and sharing it with the world through the Free Software Foundation. The word "free" in this context is often misunderstood. It refers to the free exchange of ideas and sharing of the brain trust. In no way does it mean software vendors cannot charge for the products and services they provide the Linux software community. In fact, in its last annual report to stockholders, IBM announced its commitment to Linux and said it has budgeted $300 million for Linux development. IBM did not share its marketing plans in the report, but it's a safe bet IBM has a revenue model as part of its plans.

TAKING UP RESIDENCE

Linux, with the help of giants such as IBM, is challenging Windows' dominance in computer operating systems. But for automation and instrumentation engineers, the story got even more interesting with the advent of "embedded Linux." Simply exchange your hard drive for a tiny and robust flash disk memory system. Remove the graphical user interface and other elements not needed in an instrument, controller, or other automation product. The operating system is an embedded system because it resides transparently inside the device.

All instruments have such a core, more accurately referred to as an operating kernel. An embedded Linux kernel and the drivers associated with it provide all the useful elements of the Linux operating system, including all its attributes, as an open source software environment.

Embedded Linux accelerates the development of feature-rich systems, shortens time to market, and greatly reduces costs.

Two years ago in late November, early in the development of our Linux-based products, we hit a roadblock. We had just adopted a new Ethernet integrated circuit, and as yet, no driver existed to integrate this device into the PowerPC processor. Without Ethernet communications, we found software development hindered.

We went home Wednesday afternoon to enjoy the long Thanksgiving weekend with this problem lingering. On Monday morning, our engineering director called me over to watch our product communicate with its development system over the Ethernet link. "Who worked through the holiday weekend?" I asked. "Nobody," was the reply. It seems our engineers posted our partially written driver on the Internet. An engineer in Germany had a similar need (they don't celebrate the U.S. holiday there). He downloaded our code, finished and tested the driver, and returned it to us.

VIRTUAL EMPLOYEES

We have no interest in making proprietary claims on simple hardware drivers; neither did our German counterpart. Our open attitude and acceptance of the open source model has added scores of "virtual employees" to our development staff. Everyone who participates in the open source software model is similarly benefiting.

One of the surprising things about Linux is its efficiency and small size. You would think that with so many programmers adding their features, it would grow in the same way Windows has. In fact, the opposite has occurred. Through advanced software management techniques and the use of application-specific conditional compilations, the size of embedded Linux systems remains quite small.

Just take a look at Sixnet's IPm Linux engine, complete with a ISaGRAF run time, Modbus support, and other features residing in just 3 megabytes, leaving most of the flash disk available for applications software. The IPm computing subsystem resides on a circuit board that is less than 7 square inches and consumes less than 2 watts of power.

New technology becomes successful in the industrial marketplace if it has popular support, if it makes users comfortable through their familiarity with it, if it exceeds expectations, and if it and provides economic advantage. In recent years, we have seen Ethernet networking expand dramatically in the industrial marketplace because it has the attributes needed for success in real-time industrial applications.

Similarly, Linux promises to match this rapid acceptance. Linux has certainly gained the attention of programmers and users alike who have been looking for alternatives to Microsoft operating systems. With its Internet connectivity and its interoperability with the huge installed base of Unix- and Windows-based systems, Linux passes the familiarity test.

DOWN THE ROAD

In the near future, expect to see Linux-based Web servers inside the instruments you install. Embedded Linux data clients will upload real-time data from the plant floor into our ever-expanding information systems. The control systems we install will finally fulfill the promise of becoming truly open through their open source software foundation.

While the users of these new products enjoy these many benefits, the designers of industrial products will also prosper. Linux provides a template for product design that allows added innovations onto the ever-increasing core of existing functionality. No longer do product designers have to reinvent the wheel with each product they design.

Linux is more than an exciting concept for computer enthusiasts. It's the template for the future of instrumentation and automation systems.

Behind the byline 

Steve Schoenberg, P.E., is president and a founder of Sixnet. He has developed advanced automation technology throughout the company's 24-year history.