What To Know About EtherNet/IP

Everybody is really busy today. Even with shrinking budgets, long time customers now in the witness protection program and postponed projects there sure seems to be a lot to do.


It might have something to do with the layoffs we’ve seen over the past 18 months. A lot of engineering staffs have been cut. IGT, one of the biggest makers of casino slots, just laid off its entire networking group. A lot of the Mass Flow device manufacturers have moved their developments to China. Rockwell has moved most of its Engineering to Singapore.


But for those of us still working here in the US, there’s still a lot of work to do. Companies have smaller budgets and smaller staffs. That means that we have the challenge of getting more done, faster for less money. It’s not pretty but who said life would be easy.


I get a lot of calls from Engineers that are looking at EtherNet/IP.  I can tell who they are right away because they ask “How much is EtherNet/IP”? That’s such a tough question for me because by nature I am a tease and a smart aleck. I’d like to look at their website, find out they make valves and say “Hey, how much does a valve go for today?” Or, “How much is a car?” All ridiculous out of context questions.


Luckily I am able to roughly grip the arms of my chair, restrain myself and be polite. I have to take them through the litany of questions that are important so that I can match our products and services to their needs.


Here’s those important EtherNet/IP Questions:


EtherNet/IP Client or EtherNet/IP Server?

This is the fundamental one. An EtherNet/IP Client makes connections with lots of servers and exchanges buffers with each of those servers. It controls the connection. Clients are devices like PLCs and PC Controllers. An EtherNet/IP Server is a device that accepts a connection from one Client and does the data exchange with that Client. Servers are end devices like valves, I/O Blocks, Drives and Motor Starters.


What RTOS or TCP/IP Stack are you using?

One of the ways that we make things simple is our RTOS and TCP/IP stack interface. Our EtherNet/IP software needs nothing, repeat NOTHING, from the RTOS. We are completely independent of an RTOS. We can easily run as part of a single control loop with no RTOS. All we need is some 10msec tick count so we can keep track of time. But we are not independent of a TCP/IP stack. We need that to get on the network. We support logs of them. I still get calls from people with proprietary, home grown TCP/IP stacks and its one of the challenges to implementing EtherNet/IP. By telling me what stack you are using, I can tell you whether you can easily import our software, if it will be a challenge or if you will need help from one of our experts.

What kind of device are you building?

It’s funny, some people protect the type of product their building like it’s a national secret. I remember a chiller company that wouldn’t release its list of register addresses without a signed license. Who knows what might happen if the Ruskies could get their hands on the inlet water temperature! All I need to know is if the device type you’re building is a common one that should follow one of the ODVA profiles. If so, then we have to talk about adding that profile. We’ve probably done it before but if not, there may be extra expense there.


When do you need to get this done?

My old buddy, the late John Lovallo (I have a hundred John Lovallo stories), used to tell me “John, you can have it cheap, fast or well? Just pick any two”. I hated that but it’s really true. If you have to have EtherNet/IP next week you really need one of our experts to do it. You need to get an Object Model done fast. You need to have a conforming EDS file done right away. You need the hooks into your TCP/IP stack. There’s a lot to do. On the other hand, if the project is a year away and you’re getting budget numbers that’s another story – we’ve got time to work out the issues and I need to know that.


How Expert are you on EtherNet/IP?

There are really three groups of people I deal with. There are the experts. They’ve done a lot of EtherNet/IP implementations. They’ve done DeviceNet and understand all the Object Model Stuff and how everything works. Then there are the people that have taken the time to educate themselves. They know a lot but not really how to get it done. Lastly, there are the people that don’t know the first thing and I’m the first resource they’ve turned to. I usually send them my book on Industrial Ethernet as a getting started gift. The point is that I can help you a lot better if I know what level you are.


There’s more but those are the top five questions you will get from me when we start talking about your EtherNet/IP implementation.