Node numbers for Controllogix redundancy

Hello Friends,

I have a redundant 1756-L55 pair.The two CPUs are in two corresponding Chasis.These are connected to two more chasis on controlnet for Remote I/Os.
For all these 4 chasis what are the node numbers?
Is there a common node number for both CPUs in adjacent chasis for redundancy?

Thanks.
Duncan

Hey Duncan, did you read the manual for the ControlLogix Redundancy System?

Anyway, you must address the I/O chassis CNBs with node no. 1 and 2. The CPU CNBs will have address 3 and 4.

I suggest you to read the manual. It's well written and gives you various suggestions in order to optimize your system and avoid problems.

I have a controllogix redundant system in service, and here is my controlnet addressing:


Primary Chassis (Chassis A) - node 10
Secondary Chassis (Chassis B) - node 11

I/O chassis has 2 CNB's - nodes 1 and 2
I use node 1 for RIO comms and node 2 for ENBT comms. This way, if there was a failure, I would immediately know where the problem was.

There was some disscussion around putting all comms on one card, but since we have spares readily accessable and within short distance, the risk was minimal.

Regarding the processor nodes - the SRM module will switch the address to the primary node number upon switchover. Thus the primary chassis is always node 10.

For Duncan:

the important thing is to assure that I/O chassis are nodes 1 and 2