ControlLogix redundancy setup

[MartyMaucher]

This might be pushing the limit of what to ask for, but some guidance in the right direction would be helpful. I'm programming this setup in Logix Designer 28.11:

Chassis 1:
1756L73 Controller
1756-EN2TR Ethernet
1756-RMC1 Redundancy module

Chassis 2:
1756-EN2TR Ethernet
<other I/O cards>


Chassis 3:
1756L73 Controller
1756-EN2TR Ethernet
1756-RMC1 Redundancy module

Chassis 4:
1756-EN2TR Ethernet
<other I/O cards>


How does Chassis 1 talk to Chassis 2 in software?
How does Chassis 1 talk to Chassis 3 - through the redundancy cards (fiber optic)?
Do the <other I/O cards> in Chassis 2 have to match Chassis 4?

This PLC architecture is more advanced than what I have worked with to date. Suggestions appreciated,

Marty.

 

[jkerekes]

You need to download the redundancy guide from Rockwell and follow it exactly. Also check the firmware required. I don't know if the redundancy firmware is out for version 28 yet. It would be something like 28.5 or so. The minor revision > .5 indicates its for redundancy.

 

[Ken Roach]

You need both the Enhanced Redundancy User Manual and the release notes for the specific bundle of firmware you'll be using. For the ControlLogix 1756-L73 controller, the most current firmware bundle is 24.052. You will find that Redundancy releases lag the general purpose firmware by a bit.

Direct link:

ControlLogix Enhanced Redundancy User Manual, Publication 1756-UM535E.

The firmware bundles are downloadable from the TechConnect website, and the release notes are right along with them. You'll also get a version-specific Redundancy Module utility.

In general, the ControlLogix CPUs in the paired chassis (what you call 1 and 3) behave like a single CPU. You download to and edit only the Primary, no matter which one is currently the Primary. The edits and data are automatically transferred to the Secondary via the 1756-RM2 module (the -RMC1 is just the fiber optic cable part number).

The I/O system does not need to be matched or symmetrical unless you're trying to create some sort of fault tolerant I/O subsystem. The 1756-EN2T modules and the I/O modules go into the I/O tree in Studio 5000 Logix Designer just like ordinary ones do.