Two CLX CPU in one chassis

Hi all. We have two ControlLogix CPU in one chassis, and a ControlLogix CPU in another chassis want to communicate with one of them through Ethernet. How should I configure the MSG? The chassis which has two CPU has an Ethernet card whose IP address is 192.168.2.1. But I cannot set path of the MSG as "B_ENBT,2,192.168.2.1", because the MSG can not distinguish the two CPU.

Greetings yang1216 ...

and welcome to the forum ...

the path that you mentioned is too short ... you need to add another step or two in order to tell the MSG to go to the chassis backplane and then which SLOT to go to ...

the information in this thread should be helpful ...

http://www.plctalk.net/qanda/showthread.php?p=325596&postcount=8

Thanks, Ron.
So, if I want to communicate with the processor in slot 11, I should set the path as "B_ENBT,2,192.168.2.1,1,11".

MSG is the hard way

CLX platform has a built in method for transmitting data. Try looking up produced and consumed tags. I think you'll find this MUCH easier. MSG's are required when reading data from a different platform controller, such as a SLC or MicroLogix. But, in your case, it's much cleaner and easier to follow using produced and consumed tags. Basically, the controller holding the data "produces" a tag, and all the other controllers, not just 1, can "consume" or read the tag. I typically name these tags in order of where they are produced. For example, lets say you had a bunch of floating point values that you wanted to transfer from PLC1 to PLC2. I would make the tags in PLC1 something like Floating_From_PLC1. If these tags have the same name in both PLC1 and PLC2, they become very easy to locate when following them, and it's also easy to know where they are generated.