Communication b/w two PLCs

Hi all,

I've to communicate the two controllogix PLC, initially I started working with "Produced and Consumed Tags" but now I came to know that "Produced and Consumed Tags" only applies to the PLCs in the same network (I'm not sure either the both PLCs should be in the same chassis, Please confirm it).

Whereas the PLCs at my side are far away and not a part of a single network.

Now I'm looking at Message command to perform, Please let me know will it work or there are limitations as well. If some one have other option then please share...

I think that you have supplied to less information now.
So what type of PLC's need to talk over what kind of communication at what distance?
How many data at what speed is also usefull...

I'm using RSLogix 5000, communication media is Ethernet.

I'd love to help, though my experience with RSLogigx is fairly limited.

But when you say they're not part of a single network, you mean they're not part of each other's LAN, right?

But that they are able to communicate with each other's networks with this ethernet?

Since you will communicate via Ethernet you will want each connected to a hub or router and both PLC's should have IP addresses in the same range (example: 192.168.10.1 for PLC "A" and 192.168.10.2 for PLC "2"). Use RSLinx to verify you can communicate both of them on this network. Once you have established communications, each PLC will need to have the other as a I/O device in its configuration and you are ready to interface via Produced / Consumed tags.

Incidentally, you are correct that Produced / Consumed tags is the right way to go. Much better than Messaging.

Steve

With a properly configured layer 3 switch you can send produced/consumed tags from one network to another. I currently have three controllers in three different chassis on three different subnets all talking with each other without a problem.

A layer 3 switch is what allows you to send data from one subnet (or VLAN) to another. The Controllogix really doesn't care how the connection is made.

Without a layer 3 switch both controllers will need to be in the same subnet. There are advantages and disadvantages to both approaches.