Control Engineering’s E-News Letter for Embedded Control – March 2001

In this issue:

Patent discussions
Trade shows
Introducing Entivity
Siemens does PCs
Best bosses look for allies
15 years of CAN
Distributed control paper from Russia
Siemens offers online training
Cool products
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Patent discussions

几乎每一个讨论在最近的国家ustrial Automation Show (part of National Manufacturing Week, March 5-8 in Chicago) eventually turned to patents. Primarily, discussion revolved around Schneider Electric’s patent infringement lawsuit against Opto 22. Some discussed the other Schneider patents that involve OPC. Software patents are controversial, at best. This one is no different. Opto 22 has said they see no infringement and will fight the suit. We’ll just have to see how this one plays out in the courts.

You wonder if patent litigation attorneys are starving. NCR (Dayton, O.), a manufacturer of computing devices and data warehousing, has sued Palm Inc. and Handspring for patent infringement. It seems that NCR has a 15-year-old patent for a hand held terminal for financial transactions. Palm has issued a statement that it sees no conflict and will fight the suit vigorously. Cognex Corp. (Natick, Mass.) served a complaint against Electro Scientific Industries (Portland, Ore.) claiming infringement on a patent for examining surface mount inspection.

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Trade shows

Attendance seemed to be down a little at this year’s event, but there were still plenty of engineers, technicians, and, surprisingly, IT people roaming the aisles and asking pointed questions of exhibitors. While people wonder about the future of trade shows, other shows seem to be doing quite well. ProMat (Material Handling Show, February 12-15 in Chicago) drew record attendance. The aisles were jammed as I was trying to get from one appointment to another around the show floor.

Did you attend NIA? Will you in the future? What could be improved? What are your thoughts? E-mail gmintchell@cahners.com . I’ll report back in a future newsletter and forward comments to the show organizers.

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Introducing Entivity

The major news of the year in PC-based Control is the formation of Entivity (Ann Arbor, Mich.). Think & Do Software was going for its second round of financing while long-time foe Steeplechase Software had been acquired by Schneider Electric. Schneider participated in this financing round by merging Steeplechase into Think & Do, forming Entivity. Schneider has a minority position and a seat on the board of directors. By forming a new company, Entivity is now able to pursue additional products and channels of distribution. The first new product is Automation ProjectNet for collaborative project management. Look for more activity.

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Siemens does PCs

The early days of PC-based control were very much an ‘us versus them’ time. PC advocates were breaking new ground using commercial standards for industrial control. The ‘stodgy, proprietary’ PLC companies were seen as standing in the way of true innovation and industry advancement.

I just had the opportunity to visit one of those ‘stodgy, proprietary’ companies-Siemens’ Software Business Unit (Princeton, N.J.). Chatting with managers and developers, I found out how far the company has come in PCs. The emphasis on PCs comes because managers see many changes occurring today. Application code is becoming more sophisticated. Data transparency is required throughout the enterprise. Engineering is moving to concurrent team design with more C++ and computer skills, while cost of engineering, configuring, and programming has become a major cost component of an automation project.

计划之一是发展的一个普遍的重击opment Environment (UDE). This is a concept that has just hit the pages of Control Engineering with force within the last year. Often looking like Visual Studio, these tools really help control engineers get a handle on programming projects. The Open Developers Kit uses ‘component’ technology to enable integrated motion, vision, and user defined C/C++ algorithms into PC-based control. Expect to see more discussion of tools like these from Siemens and others in future issues of Control Engineering.

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Best bosses look for allies

‘Managing is getting paid for home runs someone else hits.’ -Casey Stengel

Dale Dauten uses this quote to introduce a recent column that I received from the Dayton (O.) Daily News about what good bosses look for in ’employees.’ When asked to describe employees he’d hired, Bruce Binkley of Waxahachie, Tex. Express Personnel office said, ‘Employees? Yuck. Who wants employees? You have to manage employees, and that takes up all your time.’ The answer? According to Mr. Dauten, look for learners who love a challenge. ‘The love of a challenge,’ he says, ‘turns a workplace into reality theater, where work becomes plot and characters reveal character.’

I’m willing to bet that everyone reading this newsletter is someone who loves a challenge. We’d better-we get plenty of them! Do we also look for this in people we hire?

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15 years of CAN

In February of 1986, Robert Bosch introduced the CAN (Controller Area Network) serial bus system at the SAE congress in Detroit. It was designed to handle short messages (up to 8 bytes), support multi-master access (collisions get resolved by priority), and offer a high degree of reliability (15-bit CRC for every message). In Mid 1987, Intel delivered the first CAN chip, the 82526. Shortly thereafter, Philips Semiconductors introduced the 82C200 CAN controller. Today, about 20 chip manufacturers produce devices with CAN interfaces and almost every new passenger car manufactured in Europe is equipped with at least one CAN network. Also used in other types of vehicles, from trains to ships, as well as in industrial controls, CAN is one of the most dominating bus protocols. In 1999 alone, close to 60 million CAN controllers made their way into applications; more than 100 million CAN devices were sold in the year 2000.

Although CAN was originally developed to be used in passenger cars, the first applications came from other market segments. Especially in northern Europe, CAN was already very popular in its early days for textile and other machine control. In the early 1990s, the time was right to found a user’s group to standardize the different solutions. Beginning of 1992, Holger Zeltwanger, brought together users and manufacturers to establish the `CAN in Automation’ (CiA) international users and manufacturers association. One of the first tasks of the CiA was the specification of the CAN Application Layer (CAL). As CAN is a pure data link layer implementation, there were no standards on how to exchange data object on an application level. Although the CAL approach was academically correct and usable in industrial applications, it had a drawback: every user needed to design a new communication profile because CAL was a true application layer.

Since 1993, within the scope of the Esprit project ASPIC, a European consortium lead by Bosch had been developing a prototype of what should become CANopen, the CAL-based profile for internal networking of production cells. In 1995, CiA released the completely revised CANopen communications profile. The CANopen profile family also defines a framework for programmable systems as well as different device, interface and application profiles. This is an important reason why whole industry segments (e.g. printing machines, maritime applications, medical systems) decided to use CANopen during the late 1990s.

在1990年代早期有一个独立的parallel development for a higher-layer communication profile: the engineers at the US mechanical engineering company Cincinnati Milacron started a joint venture together with Allen-Bradley and Honeywell Microswitch regarding a control and communications project based on CAN. However, after a short while, important project members changed jobs and the joint venture fell apart. As a result, Allen-Bradley and Honeywell continued the work separately. This led to the two higher-layer protocols `DeviceNet’ and `Smart Distributed System’ (SDS), which are quite similar, at least in the lower communication layers.

In early 1994, Allen-Bradley turned the DeviceNet specification over to the `Open DeviceNet Vendor Association’ (ODVA), which boosted the popularity of DeviceNet. Honeywell failed to go a similar way with SDS, which makes SDS almost an internal solution by Honeywell Microswitch. DeviceNet was developed especially for factory automation and therefore presents itself as a direct opponent to protocols like Profibus-DP and Interbus. Providing off-the-shelf plug-and-play functionality, DeviceNet has become the leading bus system in this particular market segment in the US.

With DeviceNet and CANopen, two standardized (EN 50325) application layers are now available using CAN, both addressing different markets. DeviceNet is optimized for factory automation and CANopen is especially well suited for embedded networks in all kinds of machine controls. This has made proprietary application layers obsolete; the necessity to define application-specific application layers is history (except, perhaps, for some specialized high-volume embedded systems).

Of course the semiconductor vendors who have implemented CAN modules into their devices are mainly focused on the automotive industry. Since the mid 1990s, Infineon Technologies (formerly Siemens) and Motorola have shipped large quantities of CAN controllers to the European passenger car manufacturers. As a next wave, Far Eastern semiconductor vendors have also offered CAN controllers since the late 1990s. Since 1992, Mercedes-Benz has been using CAN in their upper-class passenger cars. After Volvo, Saab, Volkswagen and BMW, now also Renault and Fiat use CAN networks in their vehicles.

Although the CAN protocol is now 15 years old, it is still being enhanced. Several enhancements regarding the approval for different safety-relevant and safety-critical applications can be expected for the higher layer protocols. Last year an ISO task force defined a protocol for a time-triggered transmission of CAN messages. The TTCAN extension will add another five to ten years to the total lifetime of CAN. When taken into account that CAN is still at the beginning of a global market penetration, even conservative estimates show further growth for this bus system for the next ten to fifteen years. This is underlined by the fact that the US and Far Eastern car manufacturers are just starting to use CAN in the serial production of their vehicles over the next few years. Furthermore, new potentially high-volume applications (e.g. entertainment) are in the pipeline – not only in passenger cars but also in domestic appliances.

Olaf Pfeiffer, CANopen

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Distributed control paper from Russia

Engineers around the world are studying and experimenting on various PC-based distributed control technologies to see what improvements can be made in the state of the art. I received this paper from Modular Systems Tornado (Novosibirsk, Russia). The paper is authored by engineers from the Institute of Automation and Electrometry, Siberian branch of Russian Academy of Sciences (Novosibirsk, Russia) and Modular Systems Tornado. It is interesting reading about using distributed control in a power generating unit control system. Hyperlinks to e-mail are included in the paper. They will be interested in your comments and suggestions.

Click here to read the paper.

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Siemens offers online PLC training

Siemens Energy & Automation Inc. (Alpharetta, Ga.) has introduced three online certification courses for its Simatic S7 programmable logic controllers (PLC). Participants completing the Basic, Advanced and Expert course of study gain accreditation as a Siemens Certified PLC Professional.

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Cool Products

Opto 22 (Temecula, Calif.) has released a PID module for its SNAP Ethernet I/O line. The module monitors an analog input signal and adjusts output signals to control one PID loop. All PID calculations are made in the module independent of a controller.

Festo (Hauppauge, N.Y.) enables locating controller and pneumatic valves closer to actuators with release of Economy Control Node. The product is a licensed Allen-Bradley SLC500 with integral DeviceNet scanner in an IP65 enclosure.

Dolch Computer Systems (Fremont, Calif.) is shipping a rugged, multi-slot portable PC powered by an Intel 1 GHz Pentium III. Other specs include 8 MB video memory, expansion card hold-down system, and two USB ports.

GE Fanuc Automation (Charlottesville, Va.) is introducing Panel i personal computer for use with its Open Factory CNCs. It is designed for typically harsh machining environments and includes a 500 MHz Pentium III processor, three screen sizes, and optional touchscreen and soft keys.

CTC Parker Automation (Milford, O.) has unveiled P1H PowerStation, a low-cost HMI workstation with touchscreen capabilities. The product weighs in at under $1000.

VMIC (Huntsville, Ala.) now offers a 1 GHz Pentium III processor on its VMIVME-7697A single-board computer. Other features include 128 MB flash RAM, three 32-bit timers, and software selectable watchdog timer.

TechnoLand (Sunnyvale, Calif.) has released a Celeron/Pentium III single-board computer with VGA, 10/100 BaseT, and integrated audio.

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