AB Redundancy Failure

I have a system consisting of two AB Controllogix PLCs, in identical configurations, sharing a gobload of IO. I found that one of my chassis shows "DISQ" on the SRM module. I tried several things to recover comms:

- cycled key switch
- replaced SRM
- replaced CNB
- replaced ENBT
- replaced L63

I have NOT replaced the power supply or the chassis.

The secondary PLC will NOT go into "RUN".

Errors recieved earlier are:

(Type 12) Redundancy Fault
(Code 32) Disqualified Secondary Became Primary

Via RSLinx on the network, you can only see the ENBT module, that's where I started. The primary CNB/ENBT modules show "no backup" or "no module in secondary". My secondary CNB/ENBT show "CMPT", and the CNB does show "!Cpt". All modules are the same type and revision. No edits exist.

This is on a running system, so I haven't been able to take down the primary. I'm starting to think that my problem may lie there instead of the secondary.

I also don't have the RSLinx configuration ability for SRM. "LITE" doesn't use it, I suppose. I have a licensed version, but will have to get it reactivated due to PC death.

Stumped. Waiting on Monday so I can call AB.

Meanwhile, I'm open to suggestions...

I suspect you had multiple failures and as result you disqualified secondary came up as a primary after power up.

First you need to resolve !CPT - see page 107
http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um523_-en-p.pdf

Next, if your secondary controller faulted, you need to go online with secondary and clear its fault

If this did not help then you need to upload SRM log files and provide them to techsupport

Yeah, !Cpt is a problem. Both modules are the same from what I can tell. I have to get RSLinx officially licensed to use the SRM utility. I can put the original module in, but still there's no result. All the faults in the secondary are clear, with exception of the disqualification in the CPU status.

Monday, Monday! Hurry up!

I can try to help you today, monday is 14 hours away

You must clear !CPT, just follow p.107 procedure
Also are you sure that both controllers have solid green OK light?

Can you post screen shots for every tab of both SRM modules

Also upload SRM logs individually from each SRM
DO NOT try to pull both logs from the same SRM - they will not be complete, get one from each.

As far as I remember SRM configuration tool works in Lite (non-activated) version
If you don't see this option then check TN 46053

TN 29511 has all versions of the tool

TN 55721 tells you how extract logs

Thanks. I'm off work, but back in the office trying to find whatever the heck those numbers are! Searching rockwellautomation as we speak.


*My RSLinx has the option for the module configuration, but nothing comes up.

**Found it.

these numbers are technotes that you can get from rockwell knowledgebase

you must have your support contract to see some of them

Contr_Conn said:

these numbers are technotes that you can get from rockwell knowledgebase

you must have your support contract to see some of them

Click to expand...

I can see the last one, we have no support contract. No help so far.

This means you will not be calling techsupport tomorrow
So make a plan B

Plan C. I'm always Plan A! I'll have to ask them why I can't see the remote config. On either computer.

You can't call if you have no contract.
Does not matter what you want to ask

Technote tells you how to install config tool if it is not visible

Hidden back in the corner of my crowded cabinet was a loose, as in "disconnected" ethernet cable that went to my disqualified processor. After I found it and plugged it in, the system recovered in about 5 minutes while I was on the phone with Plan D....

Add this to your list, "EVERYTHING has to be connected." We had a lightning strike a few weeks ago, and this apparently was not plugged back in.