Logix Redundancy Problem - Lost programs on all PLCs.

[harryting]

Well, not sure what else we can do with this one at the moment. Will chat with Rockwell in the morning but am not expecting much. Guess I'm posting just to share the experience.

This is a established system running for over 10 years. The only hardware change were a network card failure a few years ago. We also had a failure earlier this year but we contribute that issue due to a network switch issue which also took out comm for two other simplex PLCs on the network.

This time, we lost all the programs on the PLCs on both Primary and Backup chassis. There are 2 PLCs on each chassis (4 total) and all were showing "NO PROG".

REcovery were fairely straight forward. Just cycled power on each rack and Primary came up fine without needing a download and the Secondary synced just fine. However, I'm losing confidence at the redundancy at this point and left the backup rack powered off.

Seems Logic Redundancy may not be worth it sometime.

L72 – 20.58, EN2T-11.002, CN2R/B – 20.22, L72 – 20.58, RM/B -3.4

 

[tlf30]

Well, considering that you are running v20 firmware, I would recommend upgrading to 33 or above. There has been major improvements to the stability of redundancy.

EDIT: Also, the RM1 modules have some major issues. Upgrading to RM2 modules would be a huge improvement.

 

[harryting]

Ok, I haven't considered that yet. Need to look at the budget and evaluate how necessary redundancy is in this situation. Thanks for the suggestion.

The rest of the plants are all on L6X processors so I wanted to keep everything V20 for consistency sake but this might have to be done.

 

[joseph_e2]

I haven't used redundancy before, but I have used v20. Based on my experience and with other reports of general bugginess, I'd lean strongly towards getting away from it if you can. Unfortunately, the L6x tops out at v20. Are you at running the latest minor rev of v20?

 

[jstolaruk]

I haven't used redundancy before, but I have used v20. Based on my experience and with other reports of general bugginess, I'd lean strongly towards getting away from it if you can. Unfortunately, the L6x tops out at v20. Are you at running the latest minor rev of v20?

The OP is using L72s which support goes a long ways up to at least v35.

 

[joseph_e2]

He also said the rest of the plants are on L6x processors. He may not be able to keep all his PLCs at the same rev, which is not a major issue, really.

 

[harryting]

So I talked to the local Rockwell guys. If go above V20 then I also need to replace the RM card with RM2 which is $8k each.

No one I spoke to have seen anything like it. The last time this very symptom happened we traced down a malfunctioning fiber port but this time we don't see any network issue.