Re: Boeing 787 integer overflow

["Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>]

On 05/03/2015 04:34 PM, Dennis Lee Bieber wrote:
> On Sun, 3 May 2015 12:03:51 -0400, Peter Chapin <PChapin@vtc.vsc.edu>
> declaimed the following:
> 
>> I guess it depends on if there is a *requirement* to reboot the system 
>> periodically (less than 8 months) in the maintenance plan. The matter 
>> should be handled somewhere and it seems like it wasn't. In other words it 
>> was just "luck" that these systems have been getting restarted frequently 
>> enough.

Apparently there isn't, since the AD is to restart the GCUs more frequently.

> 	Also depends upon just what "reboot" means in this environment... If
> this is some sort of elapsed time counter, then it is something saved in
> flash memory and will survive a normal power-cycle operation.
> 
> 	"Reboot" in this case may mean erasing and reloading the operational
> flight program, databases, and other stuff in "permanent" memory.

Since the Ad is to restart the GCUs more frequently, it doesn't appear to be
that complicated. It also says that the effect of the overflow is for the S/W to
go into a special mode, so it's clear the S/W detects the overflow somehow.

-- 
Jeff Carter
"My little plum, I am like Robin Hood. I take from
the rich, and I give to the poor. ... Us poor."
Poppy
96