PLC Modicon EtherNet connection

Good-day everyone.

I am doing a project with Modicon, however I am currently stuck at controlling PLC via EtherNet .

An example that basically demonstrate my problem:
PLC1 control LED1 - controlled by a button
PLC2 control LED2 - always ON
When LED1 ON, LED2 goes OFF automatically.
Both PLCs have IP@ and connected to an EtherNet network.

My goal is nearly achieved, any help is appreciated.

Hi there,

Firstly, we need to know what PLC exactly (not just Modicon, that could be anything from the late 80's through to a modern processor now, hundreds of models) and what software you're using to program it - Unity Pro maybe? Or is it a more basic processor?

Then we can help.

Sorry, I forgot to include the detail.
Both PLC are Modicon Premium TSX P573634
The software I use is Unity Pro.
Thanks for your quick reply Saffa

The easiest way is to use io scanning (search in the help for a full description). Basically you create a table in the comms section (it is a tab on the ethernet setup) and the plc does the rest. Just make sure you have located the tags (set them to an MW address) in the source plc.

We use the method Geoff has described, however it's between remote I/O racks and a main PLC, not PLC to PLC so I can't comment on that. There are messaging FBs which can be used to read / write %MW values, but I've never used them so other than saying "look in the help file", I can't help you much there. There are some reasonably straight forward examples, but as with most Schneider help files, they're preeeetty basic.

There is also another method called Global Data or something like that. Basically you can set up a small set of "shared" memory which all controllers will broadcast to the network. It does require your network be able to support multicast though. Again... haven't used it, just read about it!

If you've got the controllers up and running and its not a production environment, i'd just try setting up one of the examples in the Unity Pro help file. Do a search for READ_VAR and look in the communications FBs and Premium/Atrium, Ethernet communication.

Thanks both Geoffc and Saffa very much. I can solve my problem at the moment by using the io scanning service which Geoffc recommended.
Now I am trying to use other two methods: Global Data & Messaging so that I can compare which one is the best method for coding.

Nice to meet you two.

Saffa - IO scanning can be used for plc to plc comms. Just finished a project linking 4 plc together using this method

Thanks Geoff, haven't had to do that yet but will certainly keep it in mind if we have to.