Rockwell Redundancy Error

Hi everyone... I'm not a AB expert.. I'm using L74 controller, Rm2 redenduncy module, EN2TR and EN2T module (on each chassis) on my control logix project and having 3 remote IO's rack on ring topology... I have use EN2TR for ring topology and EN2T for scada communication. The problem is my controllers are not synchronising on fibre optics... I have to connect both EN2T modules with one an other for controller's synchronisation. They are syncing over ethernet but not over optical... your help is appreciated



Thanks in advance

[FONT=&quot]Basit Jamil[/FONT]
[FONT=&quot]This is normal.[/FONT]
[FONT=&quot]The Redundant controllers will not go to SYNC if any of your Ethernet modules don’t have a valid connection. Once commissioned, loss of an Ethernet connection is a trigger for a processor swap. They are not syncing over the ethernet but it can be a backup.[/FONT]

Thank you for you response... but all my modules connections are fine... EN2T modules connected with the ethernet switches... when I connect both switches "SYNC" status comes... but when the both switches are not connected with each other I get disqualified status

Not sure if I'm understanding you correctly but BOTH the fiber (between RM2) and ethernet (between EN20--) need to be connect in order to sync.

With ControlLogix redundancy primary and secondary Ethernet modules must be able to see each other on the network, this is exactly what your are seeing.
Fiber cable between two RM2 modules is used to cross load your program and data.