Control Logix Ethernet/IP remote racks & Processor

I'm working on a control system for a test stand that would involve 8 Control Logix racks, 2 Panelview Plus touch screens, and 2 processors.

There will be a master processor that will run the test stand, and the second processor will control a high speed hyraulic load bank. In one mode the hydraulic PLC will accept commands in from analog inputs in its chassis. In the other mode, I wanted the hydraulic PLC to recieve its commands from the main PLC. All of the racks and processors are communicating over Ethernet/IP and I am using ENBT cards.

How should I be setting up the Comm Format in the ENBT configuration? Right now I set all of them to Rack Optimization, even for the remote rack with the hydraulic PLC. Something is wrong because I am not getting any data, and if I set the rack sizes correct in each processor program, I cannot go online with both processors on the network.

Maybe these couple suggestions will point you in the right direction. I read through your setup a couple times. I am not sure which processor you want to control what. For starters, each card can only be "owned" by one processor. Other input cards you can "listen only" on with the other processor. For outputs you could send that information over to the other PLC which controls the output card.

The second part, what does 'cannot go online' detail? Can you see the processors in RSLinx? Before that even, can you see all your racks in RSLinx? If you can see your processors you should be able to go 'online' with them. Online in that sense does not mean they are running however.
If none of this is new for you, then please post more details about the setup and exact problems, I am sure someone here can help.

The hydraulic PLC (Rack 7) will be a slave of sorts to the cell control PLC. It will get status information and commands from the cell PLC. The other remote racks and HMIs will interface with the cell PLC.

2nd part: I had the Rack 7 PLC and cards in my cell controller PLC program on the I/O structure list. I had all the ENBT modules in the list set to Rack Optimization, and I had I/O cards from the Rack 7 listed in the setup, I think that was part of my problem. I had some code that was looking at fault information from those cards with the cell PLC. What I ended up doing was deleting the Rack 7 cards from the cell controller program, leaving all the ENBT modules in Rack Optimization, and now I can go online with both processors at once, and they are passing consumed and produced tags back and forth.

When you speak of Comm Format, it sounds to me like you are in a CNB module, not the ENBT. The ENBT is very straight-forward Ethernet stuff.

The CNB's require that their hardware switches be set to a unique number within that group of chassis. Then make the software configuration agree with the hardware switches.

Perhaps you can provide a few more details on your configuration goals (besides the obvious "I just want it to work!"). I've recently configured a number of CNB's and ENBT's, so I may be able to help.

In my main controller tree in RSLogix5000 when I add an ethernet card for the remote racks, I get a "Comm Format" drop down box. I can select Rack Optimization, None, or Listen only - Rack Optimization. On the racks that have a processor in the rack, I do not get the Comm Format selection box.

I discovered that I was trying to make the main controller communicate with (own) the I/O cards on the hydraulic PLC rack instead of just listen to them, that was probably causing at least some of my troubles. I am still pretty new with the Control Logix platform so I don't know a lot of the rules yet.

Configuration wise, I want the main PLC to talk to the HMI's and remote racks over ethernet. The hydraulic PLC will control its own I/O, and recieve some commands and status bits from the main PLC over the local ethernet network via produced/consumed tags. I would like to monitor I/O on the hydraulic PLC rack with the main PLC for safety purposes.

Make sure you are adding just the remote ENBT card and the remote CPU under that to your configuration - no remote I/O cards or anything else. Like you mentioned before this causes the local CPU try to take control of the remote cards, which the other CPU will not like. As for the comm format, try using None.

I tried re-adding one of the remote PLC owned I/O cards with the "Listen Only - Float" Comm Format on the card itself, and the problem did not come back, so I think I can safety monitor the I/O with it set that way.

I just didn't know any better the first time I set up those cards and the PLC's were probably "fighting" over them. I think I'm starting to get the picture of what I did wrong and what I need to do now. I got the produced/consumed tag thing working yesterday, and the PLC's aren't fighting anymore so I'm in much better shape. I just wish the boss would've let me try this out on a smaller project first...