Control Logix 5555 & Ethernet/IP I/O

Hello Allen Bradley experts!

I wonder if what I want to accomplish is feasible, I hope you guys can point me in the right direction or let me know not to waste my time... or perhaps indicate alternative solutions.


I want to open an Ethernet/IP I/O connection to a Control Logix 5555 Allen Bradley PLC. The connection would be used to read a block of Input data and write a block of Output data every 50 milliseconds. Blocks would be about a couple of hundred bytes.
(I have already developed this solution for another Ethernet/IP device, an Anybus X-Gateway).

In this setting the PLC would kind of be the slave and I am not sure this is possible.


Thanks in advance for any information on the subject!

This is called "Produced/Consumed Tag" data exchange in the ControlLogix.

It is a little more complex than creating an I/O connection to an Assembly Object, because you have to specify the Tag Name and the path to the controller.

But it uses the same basic principles.

Do you have some kind of toolkit, or a subscription to the ODVA specification ? You're not going to be able to sell your product commercially if you don't test it against the ODVA certification test set.

Thanks Ken,

How big can I make the "Produced/consumed Tag"?
In other words, could I include all my data in one Tag or would I have to create one per value transferred?

We have the ODVA specifications but basically nobody connects to our Ethernet/IP object: it is a client only and acts as a driver to send and receive data from Ethernet/IP from our own applications.

All right, I have seen an example where a Tag was an array so that should do the trick.

The maximum size of a single Produced/Consumed tag is 500 bytes.

That will do 500 SINTs, 250 INTs, 125 DINTs or REALs.

Yes, that is enough for me!

But I've just read a document from Rockwell:
http://www.rockwellautomation.com/enabled/pdf/ioclogix1_0.pdf
It shows that an I/O connection can be opened with a Control Logix PLC but that it must be the master. So I guess I could modify my client to accept incoming connections and it might also work.

I wonder which of those 2 options is best or simplest?