Is it practical to use Ethernet for all industrial networking?

As industries seek to consolidate and reduce the variety of networking approaches, how far can you go?

03/09/2012


Dear Control Engineering: I was reading the article and watching the video about replacing various networking protocols with Profinet. I understand the desire to have fewer protocols, but is this a practical solution?

The variety of networking protocols that we have available grew out of a desire to have the right tool for the right job. Engineers have always wanted to match the network to the needs of the application. Here are some basic considerations:

• How much information has to be communicated?
• Does the system need to carry power to individual devices?
• Must the devices operate in a hazardous environment?
• How fast does the communication need to be?

Ethernet can work in just about any situation, but there are exceptions. To use a crude analogy, let’s say you wanted to reduce the variety of cars and trucks on the road so you could simplify repairs, manufacturing, etc. If everybody drove the same vehicle, maintenance would be much easier to deal with. So you give everyone a full-size white utility van. Problem solved. If you need cargo, you’re covered. Ladders? Put on a roof rack. Big family? Add seats. Some modifications are possible, but everybody has the same platform. Maybe it only gets 10 mpg, but it’s standard. That’s sort of the way it is with Ethernet.

Like a big van, Ethernet is good at moving large amounts of data, it can be fast, and it can carry power to devices. If your van is full of cargo or people every time you drive it, it all makes sense. But, if you commute 20+ miles to work and it’s just you, it’s lots of vehicle to move one person. A small car would be much more efficient for commuting.

Historically the thought of moving Ethernet to the shop floor was pooh-poohed because it was overkill: far too much expensive overhead for low-data devices. But the picture has changed. There are fewer low-data devices, and Ethernet is not as expensive. Field devices that used to be very simple have become more sophisticated and gained diagnostic capabilities. The infrastructure to process Ethernet-based data is less expensive, so the two extremes are moving closer together. If that big van can get 50 mpg and costs $10,000, maybe you won’t mind driving it all the time.

The challenge will be converting users and equipment manufacturers. More field devices that used to communicate via an analog signal or a fieldbus protocol will need to be changed to Ethernet. Users can’t make the change until those devices are available. Manufacturers won’t make them until they see demand. It’s an evolutionary process, and it could take some time for it to become a groundswell. Nonetheless, such technological changes are happening faster these days than they have historically, so don’t be surprised if it becomes a reality faster than you expected.


Here’s an explanation of how to evaluate an application and select the right networking tool.

Here’s a discussion on this topic from three years ago. How much has the situation changed?

Peter Welander, pwelander(at)cfemedia.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.