RSNetWorx for ControlNet using multiple CNBRs in processor rack

I have an application that requires three 1756-CNBR modules in my processor rack (1756-L63). They communicate with 13 remote I/O racks each having one CNBR. I need three to increase my bandwidth and I can't use a CN2R due to issues with mixing EWEB and RM modules (I'm using firmware 16.56 for redundancy). For the time being I only have my primary rack powered up with the RM module removed while I establish my ControlNet network.

Two questions:

1. Is it normal for RSNetWorx to show three processor racks each with one connection to the ControlNet network rather than one rack with three connections? When I re-configure it offline to show all three connections in one rack I have comms issues.

2. Is it absolutely necessary to specify a .xc file for the CNBR modules in RSLogix5000? Everything seems to work fine with no file specified for any of my CNBR modules.

Appreciate any feedback.

Sounds like a neat application !

Your requirement must be for "bandwidth" of the 1756-CNBR CPU, rather than literally bandwidth on the ControlNet network. Separating out the three CNBRs so they are on individual ControlNet physical segments will give you the most bandwidth on the wire.

The RSNetworx graphical display doesn't deal gracefully with multiple bridges per chassis, so the display of three different chassis for the three "root" ControlNet bridges is normal.

It is not absolutely required that you enter the *.XC file path into RSLogix 5000. That's done so that edits to the I/O configuration are applied to the offline copy of the *.XC file, so you can estimate ControlNet bandwidth offline. Sometimes it is simpler to just disassociate .XC from .ACD and run RSNetworx separately on the CNet segments.

Thanks, Ken. You're right, my concern was CNBR CPU bandwidth, not so much the network bandwidth.

What's the trick to re-assigning connections from one CNBR to another once the network has been downloaded? I re-assign the module to the desired CNBR in Logix and download it. I then have a heck of a time getting Networx to change the connection assignment. Seems like I have to go back and forth downloading the .ACD and .XC file a few times each before it finally takes. I assume it's got something to do with the keepers.

Also, is there a way to import the RSNetworx online I/O layout into RSLogix rather than entering each module and its configuration information into Logix individually? I miss the feature of Logix500 where you could hit the Read I/O Config button and poof, there it was.

I'm using a diagnostic program I believe you wrote called CNet_Status that tells you the connection status of each I/O rack and whether A or B is the active channel. Works great!