Allen Bradley ethernet communication

I have a AB 1769-L32C controller with build-in ethernet. I also have a 1756-L61S controller with a 1756-enbt ethernet controller in rack. I have a normal switch between them. I need to get ethernet communications between them but have no idea how to set it up ?
Can someone please help me ?
Do i need to add the oposit ehternet controller on each plc ?
I asked a guy wich was born with Omron plc. He explained and showed me that in omrom it is called datalink and it seemed very simpel, but i cant find such a function on Allen Bradley.

I searched online for an anwser but failed.

I think your one PLC is a 1769-L32E, not C if it has ethernet. It sounds like your hardware is complete. Now you have to write code to pass information back and forth. You can use messaging statements or use Produced and Consumed tags.

There is a very thorough user manual covering both Message commands and Produced/Consumed Tags in the Logix family of controllers.

Download publication ENET-UM001, "Ethernet Modules in Logix 5000 Control Systems" from the literature.rockwellautomation.com website.

Be careful with the L32C processor. If you see a connection on there that looks like ethernet, it is not ethernet and DO NOT plug an ethernet cable into it. You can damage the processor.

Verify for certain which CompactLogix controller you have.

OG

Thanks and a question

Thanks for the reply!

First i have a correction, it is a 1769-L32E, not C, controller i have

I am working with the consumed/produced tag solution and have the communication up and running from the 1769-L32E ( producer ) to the 1756-L61S ( consumer ).

I have also made a producer connection on the 1756-L61S.

I have my 1756-enbt/a on my I/O configuration on my 1769-L32E.
But when i try to make a consumer connection, i cant find my producer in the drop down list in the "Consumed Tag Connection" menu. I have attached a image of this. Can anybody help me ?

It does however make some tags by its own. Also image attached. I have tried making an alias for these but it did not work for me.

Also i have attached a image of the I/O configuration.

Hope this helps you help me

Also i would like to hear if you have any experience with making some kind of handshake to ensure the connection/data ?

mikkel said:

I am working with the consumed/produced tag solution and have the communication up and running from the 1769-L32E ( producer ) to the 1756-L61S ( consumer ).

I have also made a producer connection on the 1756-L61S.

I have my 1756-enbt/a on my I/O configuration on my 1769-L32E.
But when i try to make a consumer connection, i cant find my producer in the drop down list in the "Consumed Tag Connection" menu.

Click to expand...

Yes you have put the enbt in the l32e, but that is not enough. ControlLogix supports multiple controllers in the chassis, and your "producer" is not the enbt, it's the controller.

Your ENBT will have allowed access to the ControlLogix Backplane, so you need to add your L61 to the configuration on the remote backplane. Then it will appear in your drop-down list - be sure to get the controller slot number correct.

Hi daba
Thanks, i have tried that, but the "New Module" option i get by right clicking I/O Configuration is grayed out, i cant click on it

You can only do it Offline on the L32E

Anytime your using Logix (5, 500, 5000) and you can't do something you want to, it's usually because you need to go offline to do it.

For all : remember after an offline mod, you will need to download to the controller, that will stop your process/machine, and erase any data that may have changed since you came offline.

Thanks

Hi daba
Thanks i did it ( or you did ) hehe
I needed to add it under the netowk module as you said. I tried to add it in the normal I/O. So thank you alot!

Do you know any form of handshaking/acknowledgement over ethernet ?

Hi Mikkel,

Glad you sorted your problem out. Now you see how "graphical" the I/O configuration "tree" is, it is easy to understand how you make connections to remote devices - just follow the "path" just as you do in Windows Explorer.

As for handshaking, I usually include a couple of BOOL tags in the produced/consumed data, so that it sets up a "free-running toggle". Like this :-

In PLC1

|   HS_In                              HS_Out

|----| |--------------------------------( )-----

|



And in PLC2

|   HS_In                              HS_Out

|----|/|--------------------------------( )-----

Obviously the "In" tag is the "Out" tag of the other device.

Then put a couple of TONs on the "In" bit in each PLC (one enabled by XIC HS_In, and one enabled by XIO HS_In). If the remote PLC stops communicating, or is not running, one of the Timers will time out.

That takes care of checking that each PLC is in RUN mode as well.

Also remember that each Tag you Produce/Consume takes a valuable and limited "connection". If you are passing more than a few tags, build them into a UDT and produce/consume the whole UDT, this will then only take one connection. A single produced/consumed tag can be up to 500 bytes in length (500 SINTs, 250 INTs, 125 DINTs or REALS).