The Ethernet wars

Profibus vs. FOUNDATION fieldbus; ControlNet vs. Interbus; DeviceNet vs. SDS; Seriplex vs. AS-Interface—the bus wars continue to rage. But a new challenger has changed the battle.Ethernet, a standard in business networking since the mid-1980s, is touted by vendors and users alike as a contender for industrial applications.

12/01/1998


Profibus vs. FOUNDATION fieldbus; ControlNet vs. Interbus; DeviceNet vs. SDS; Seriplex vs. AS-Interface—the bus wars continue to rage. But a new challenger has changed the battle.

Ethernet, a standard in business networking since the mid-1980s, is touted by vendors and users alike as a contender for industrial applications. The TCP/IP protocol over Ethernet has become the Internet standard. Recently, organizations responsible for Profibus, ControlNet, and FOUNDATION fieldbus (FF) have announced intentions to support Ethernet and TCP/IP. According to Mike Evensen, director of business development for Hirschmann Network Systems, these groups are getting involved with Ethernet because their users are requesting faster, open, interoperable networking with worldwide support.

Wrapper technology is being used as the fastest way to get traditional fieldbuses on Ethernet. Developers take the core functionality of the network and "wrap" it in a TCP transportation frame, compatible with existing Ethernet infrastructure.

Says Mr. Evensen, "In the short term, the automation marketplace will have competitive TCP/IP solutions that are not interoperable. However, if the physical architecture is the same, there's still a huge benefit to the end-user."

For example, two PLCs running two different application layer protocols, such as FF or Profibus, could sit on the same wire but they could not communicate with each other. Ethernet is merely the transmission highway. As an analogy, coworkers need common application software to share a PC-based file on the company intranet. Similarly, control devices need compatible communication software to share information over the same Ethernet wire.

Additionally, automation applications require network hardware that can withstand harsh demands of the industrial environment. Hirschmann has developed "hardened" Ethernet switches, which are hardware solutions that prevent data collisions on the network. A 10-port switch, that might link one PLC and nine I/O blocks, provides each port with a free access lane to the Ethernet highway.

"For Ethernet to be successful in industrial automation," says Mr. Evensen, "you must have these three things:

  • Fast Ethernet (100 Mbit/sec) to guarantee performance;

  • Ethernet switching to prevent collisions; and,

  • A prioritization scheme to deliver determinism."

Control manufacturers, in the near term, will deliver solutions based on traditional networks, even if they do run on Ethernet. This will provide competitive differentiation among different vendors' products. In the future, however, we may see adoption of a standard Ethernet application protocol for automation. Whether it's FF, Profibus, ControlNet, or one of the dozen or so current and future options remains to be defined.

Connect and be counted

In the interim, Control Engineering wants to know what networks you use in your automation applications. This month we are mailing an Industrial Networking survey to a 10% sample of our readers. If you receive the survey, please take a few minutes to complete it and send it back. Other readers who would like to participate can complete the survey on our web site at www.controleng.com/network.htm . We'll award a Palm Pilot in a random drawing of web site survey participants.

Results will be published in a special report to our readers with our March 1999 issue. Thank you for participating in a survey designed to define the industrial networking marketplace. Your answers will help deliver better solutions for your networking systems.


Author Information

Jane S. Gerold, Editorial Director jgerold@cahners.com




No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.