Rockwell Automation has continuously improved the capabilities of EtherNet/IP EDS (Electronic Data Sheets) and AOPs (Add On Profiles) over the years. This is a very important topic for a lot of device vendors. The device integration of an EtherNet/IP™ device can be really frustrating to customers. If your competitor is better integrated and his customers can get integrated faster with his equipment than using yours – that’s a HUGE problem.
This document is designed to keep you up to date with all the different options. Use it in conjunction with the more technical and complex EDS AOP Logic Designer Guidelines that Rockwell publishes (Rockwell Automation Publication 1756-CO003A-EN-E – April 2012).
Truthfully, you don’t need much of an EDS (Electronic Data Sheet). In fact, you could just do a short, stub EDS and be done with it. You include the basics like vendor name, product name, revision and such and you’re done. What does this get you? Well, number one you need an EDS to pass EtherNet/IP conformance testing. This gets you past that hurdle. And if you have a really simple device like an 8-bit valve controller, a stub EDS will do you just fine. Your customer doesn’t need much more.
A stub EDS file doesn’t provide anything to RSLogix5000. Your device is simply a generic device and your customer has to enter the IP address and lengths of your Input assembly and Output assembly. RSLogix5000 pretty much ignores it just like the fat kid at the Prom.
If you want a little more than a stub you can describe your configuration data, assemblies and other information in the EDS. RSLogix5000 will load your EDS and use it. Here’s what it will do with a simple EDS file:
The big problem with the Simple EDS is that I/O assemblies are just byte arrays of I/O. Your customer has to know that bytes 4-7 are Analog Inputs and that those bytes must be converted to a Floating Point Tag. In other words, it requires your customer to work – never a good thing.
What a lot of vendors do is to define UDTs (User Defined Tags) for the Input and Output byte arrays. With UDTs your customers can use names to access the data fields of your Input and Output assemblies.
Another issue that you have to contend with here is that your EDS has to not only be a valid EDS file (as defined by the EDS Checker Tool and the ODVA specification) but it also has to correctly implement a number of other EDS features required for Rockwell PLCs. RTA can help you over that hurdle.
A cool feature of RSLogix 5000 is the ability to create Add-On Instructions. This mechanism allows you to define your own instruction. You can make an instruction that contains a commonly used set of instructions (or an algorithm) and use it as one instruction.
This means that you could create an AOI that knows how your Input Assembly should be decoded and how to assemble your Output Assembly. So, if you have a flow meter Input Assembly with a 4 byte Floating point temperature followed by a 4 byte Floating point flow rate, your AOI can put that data in the Input assembly in the right order. Output Assemblies work the same way in the other direction. Your customer simply has to indicate where the input data is stored and where to get the output data. Not a perfect solution but really not bad either.
If you want to get more sophisticated and give your customer the ability to access the items in your I/O Assemblies as individual tags, you’ll want the RA Licensed AOP. You have to go to Rockwell, get their blessing and a special hash tag for your device. With that hash tag in your EDS, RSLogix5000 allows you to do everything you can do with the non-Licensed EDS plus map your I/O data directly into ControlLogix Tags. Your customer can easily access the fields of your I/O assemblies using the names you define.
As with the non-Licensed EDS AOP you have to ensure that your EDS is a valid EDS file (as defined by the EDS Checker Tool and the ODVA specification) and meets the requirements unique to Rockwell PLCs. RTA understands those requirements and can assist you with that.
Make note that access to this capability is not guaranteed but most vendors products are approved for EDS AOP licensing by Rockwell.
I am calling this the PLATINUM option because it’s the top of the line, most sophisticated integration you can achieve. With this level of integration your device is as integrated into the RA architecture as well as any one of their devices. Your Configuration and I/O Assembly data are completely integrated and accessible from RSLogix5000. Your customers get range checking, automatic Tag mapping and everything else RA customers get with RA devices.
Rockwell builds special functionality right into RSLogix that can do just about anything. It might be special functionality to do unique configuration, it could launch some other software program, just about anything is possible.
You have to be a really close partner of RA to get this level of integration. It’s not for everyone. And it takes a fair amount of time. You have to get accepted, send your device and EDS file to RA and they do the integration for you. You had better have a completely stable product as this isn’t something you can easily update a couple of times a year.
|Simple EDS||Non-Licensed EDS AOP||Licensed EDS AOP||Custom EDS AOP|
|Installation?||Manually by User||Manually by End User||Manually by End User||RA Installation Tool|
|Configuration Tags||Not Available||Selectable within Logix with Enumerations||Selectable within Logix with Enumeration||Selectable within Logix with Enumeration|
|Parameters||Not Available||Not Available||Selectable||Selectable|
|I/O Tags||Not Available||Byte Arrays||Selectable within Logix||Selectable within Logix|
|Validation||EZ EDS||EZ EDS Plus Special RA Requirements||EZ EDS Plus Special RA Requirements||EZ EDS Plus Special RA Requirements|
|Special Configuration Process & Device Specific Options||Not Available||Not Available||Not Available||Device Manufactuer Specified|
|Cost||Included with RTA Stack||Included with RTA Stack||Included with RTA Stack (Device Mfr Must Get Key from RA)||RA Time and Materials|
John S. Rinaldi is Chief Strategist and Director of WOW! for Real Time Automation (RTA) in Pewaukee, WI. With a focus on simplicity, support, expert consulting and tailoring for specific customer applications, RTA is meeting customer needs in applications worldwide. John is not only a recognized expert in industrial networks and an automation strategist but a speaker, blogger, the author of over 100 articles on industrial networking and the author of six books including: