“DeviceNet is Dead” – Revisited Ten years Later

About ten years ago I got myself in a world of trouble. Big Trouble. I sent out a newsletter with the title “DeviceNet is Dead”. Basically I said that Ethernet would dominate the factory floor in the future. Valid point but the tile was extremely incendiary.

And arrows from the world over rained down on me. Rockwell was pissed. DeviceNet Vendors were pissed. Some proposed throwing me out of the ODVA. Eaton Cutler Hammer called to complain.

One of the marketing flunkies over there called to complain that their customers were calling them and wondering if DeviceNet was obsolete and what the plan was to move to Ethernet. He kept repeating how many customers were calling and the burden they were under having to “talk to their customers” about the future and their future product plans. The irony of this was completely lost on him.

My response was that I didn’t care. The fact that they had to talk to customers was not going to make me lose sleep at night. Between their customers calling and the starvation in sub-Sahara Africa I wasn’t much concerned about them.

So, it’s ten years later. Where do we stand with DeviceNet, and for that matter, Profibus DP. Are they dead? Is everything going to Ethernet?

I have to tell you that the future for these technologies is not all that clear to me. I can make the case either way.

I do know that processors are getting more sophisticated and have built-in Ethernet functionality. The low level processors that are usually used with DeviceNet and Profibus are becoming more rare and gradually being phased out. So the technology trends seem to indicate a move to Ethernet.

The configuration trends also point to Ethernet. Having web-based configuration, monitoring, diagnostics and the rest is important. And you can’t do that as well on DeviceNet. End users like the ability to access a web page for a sensor from their smartphone to check on device status.

Is there any advantage to the Profibus and DeviceNet networks? Well, comfort. People have been using these for a long time. They provide good, near deterministic response. They are actually very good for the kinds of applications where they are used.

The only disadvantage of Ethernet is the star architectures you have to use. Buying lots of big switches is not attractive. But with the increasing deployment of devices with built in Ethernet switches, all that goes away.

So what will happen when the next line that is built? Sensor bus network like DeviceNet or Profibus? Or some Ethernet? I’d guess Ethernet. Ethernet is so pervasive. It has almost no disadvantages other than the switch issue and integrators and end users are just as comfortable with it as they are with DeviceNet and Profibus.

So, my announcement that DeviceNet is Dead was a little premature. Ten years later, it might still be but the fat lady is starting to warm up. I won’t expect to see much new DeviceNet and Profibus when I write an update to this blog ten years from now.