Rules for Open Systems

The original versions of this article was published in
Industrial Controls Intelligence, October '99.

Everyone in the industrial automation seems to be waiting for “fieldbus” - the bi-directional communications protocol used to connect field-level instruments and controls. The IEC/ISA SP-50 international fieldbus specifications are still under development, with strong demands from major users and support (at least lip-service) from most of the instrument vendors. But the standard will never emerge - and here is why.

Definition of "standard"

The definition of a "standard" is simple - operating characteristics that everybody follows. Therein lies the rub - someone has to be the leader that others follow. The idea that committees composed of both users and vendors can set standards is futile. Users may perhaps be able to collaborate; but few can invest the time or expense necessary to drive a standard. And vendors can seldom agree - they are, after all, in direct competition with each other, each seeking to develop technology and market advantages over the other.

Who benefits from standards?

It must be recognized that end-users are the primary beneficiaries of standards - which provide openness and interoperability between products from different vendors, reducing products to the level of commodities. However, no single user is large enough, or strong enough, to demand and set horizontal standards. GM tried to do that with MAP and failed. Indeed, there is still some speculation whether or not the famed Michael Kaminski of MAP fame was just another GM experimental robot.... And GM continues to write "white-papers" on 1131 and similar proposed standards, but that's all they will remain - white papers.

Vendors want proprietary differentiation, which generates higher margins. Technology development is expensive and everyone understands the financial rules for expense amortization or write-off. Once the status of a standard is achieved (through technology and/or marketing leadership, or timing) other vendors will simply be required to conform - giving the clear advantage to the owner, or consortium, that controls the standard.

Rules for Open Systems

These conflicting objectives continue to cause endless debate. To help clear the confusion, we must understand that technology developers need to recoup their investment through one of the following rules:

  • Rule 1 : Licensing the technology. This may be through up-front fees for technology transfer, or per-copy sales of ASIC chips, hardware, software or firmware.

  • Rule 2 : Making everything open and free, to expand involvement. The developer is far ahead on the learning curve and followers contribute to the leaders leadership.

  • Rule 3 : Introducing "free" open technology to combat the entrenched position of a dominant market leader.

Industry examples

I am not sure why some vendors "pretend" that they are simply giving away their technology freely for everyone to utilize. And other vendors continue to argue that what they support is indeed "free and open". Siemens supports Profibus because it was one of the original developers and continues to gain advantage through its proliferation (Rule 2).

Everyone recognizes that Allen-Bradley (Rockwell) had the developers advantage when they made DeviceNet (and then ControlNet) "open". It is abundantly clear to all the members of the Open DeviceNet Vendors Association (ODVA) that the vast majority of sales of DeviceNet products are from A-B. Other "followers" of the standard, like Cutler-Hammer (who hired one of the original A-B developers of DeviceNet) had hoped to wrest leadership away from A-B through enhancing the standard. But, they simply poured their development and marketing dollars away till they recognized the futility of the exercise. It is almost impossible to unseat a market-leader through following.

The A-B strategy in making DeviceNet "open" follows a combination of all three of the rules. They allowed other vendors to purchase or license their hardware, software and firmware (rule 1); they expanded involvement through gaining a bunch of followers, all eager to find new ways of connecting to the vast A-B installed base of PLCs and controls (rule 2); and, A-B was combating the encroachment of Profibus DP and Interbus into their US backyard (rule 3).

Some think that there is another rule - submitting to user demands. The story goes that General Motors demanded that A-B make ControlNet "open" before they would use it. And A-B did just that - they made it "open" - and allowed GM to think that they were acquiescing to their demand. But, A-B was simply following the 3 rules, as they did for DeviceNet. To use ControlNet, you almost certainly need to purchase A-B ASICs and toolkits. Sure you can buy something vaguely similar from SST or other hotshot developers, but that is simply paying A-B through the backdoor (Rule 2).

Other famous "open" battles

Take a look at some of the other famous "open" battles. DOS became a standard (and made Microsoft rich) through the myopic munificence of IBM. IBM thought they'd sell PC hardware to catch up with Apple, but the hardware soon became a commodity. The only non-commodity was DOS - you had to pay a license to use that. IBM then thought they'd win with OS/2, but their previous largesse had already made Microsoft too powerful to catch and they got upstaged with Windows. It was a combination of timing (for Microsoft) and marketing mistakes (on the part of IBM).

There are several similar examples in the vast growth of the PC business - Unix and Windows; PC/AT bus and IBM PS/2; Novell and NT networks; EtherNet and ARCnet. Remember WordStar and then WordPerfect playing a losing battle against Microsoft Word and Excel? Well now, Scott McNealy has announced that Sun will be giving away their office suite to combat the entrenchment of Microsoft Office. Would you like to bet who will win that marketing battle?


There is one exception to Rule 2: The US Government (ARPA) really gave away the Internet - and caused a new revolution. Perhaps there is a lesson to learn there.

For your homework - see if you can trace which of the 3 rules are being used in each of the marketing battles in your own business. To lighten your burden, someone can perhaps give us a tune for this little ditty:

Industrial networks bring lots of gains
But that brings with it lots of games

The fieldbus wars cause a lot of fuss
The Users want an Open bus
The products made by Vendor A
With Vendor B must plug-and-play

The Vendors simply can’t agree
To make a fieldbus cheap, or free
The committees they just twist and turn
They argue out and then adjourn

De facto standards win all debates
Ask Microsoft and Mr Gates.

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