1747-BSN - Backup Scanner Module...
SLC Backup Scanner (1747-BSN) module option...
1. You have specified SLC 5/05 processors
X
2. There are likely to be local I/O modules used
X
3. Redundancy would require duplication of the entire chassis or chassis'
X
When I read this thread I initially thought of the above module but, after further consideration, and in particular the above points, it would not be suitable.
1. It does not provide redundancy for Ethernet communications
2. It does not provide redundancy for local I/O
3. It would require duplicate chassis configurations which may prove cost prohibitive
Still, I think it important to mention it's existence, lest folks think there may be no redundancy options available to the SLC platform...
19378 - 1747-BSN Frequently Asked Questions
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However, even if there was a suitable redundancy method, and more specifically one that allowed a failover secondary processor in the same chassis as the primary, I would not recommend it here. For similar reasons to others, it would not be the best way to combat the ingress of water to the enclosure. This sort of thinking should really not be entertained. If water is able to reach the chassis, and let's say both a primary and secondary processor are located in this same chassis, then it would be highly likely that any water attributed damage could potentially take out both processors at once i.e. the whole chassis is exposed to the possible risk.
I would advise as aforementioned - keep the spare SLC 5/05 processors on the shelf and realize the impact in time to swap out in the event of a failure. But remember, with water, it may not only be the processor that ends up damaged. Other modules or even the chassis itself could also need replacing. You would have to carry a full compliment of spares for the entire configuration.
The best recommendation, in my opinion, is for them to try and resolve the water ingression issue. Or move the equipment, if at all possible. If that cannot or realistically will not be acheived here, and redundancy is the only option, then you would have to migrate the entire system to a redundancy compatible platform where the backup chassis is remote from the risk. But, if that were achieved, then it could be argued to just run the system from the remote location instead, without any redundancy.
The spare SLC 5/05 processors are, I'm afraid, exactly that - spares.
P.s. The battery LED indicator (BAT) should illuminate when the battery is disconnected or low. Also, the battery low system bit should be set. It is possible that a 1747-BAJMPR battery jumper is in place, which prevents the BAT LED from coming on?
Regards,
George