Someone did the math, suggested 40(?) bit microseconds

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Post #433,384 by drook 4/4/20 10:47:47 AM 4/4/20 10:47:47 AM Reply	Someone did the math, suggested 40(?) bit microseconds 32 bit milliseconds overflows at 49.7 days so rebooting every 51 wouldn't help. Because of their high speed planes might use microseconds for more accurate positioning. -- Drew
Post #433,395 by a6l6e6x 4/4/20 9:59:20 PM 4/4/20 9:59:20 PM Reply	It must depend on what part of the many subsystems are monitored. Summary information for pilot instruments is probably OK with milliseconds. You are right that some subsystems need more precise resolution. GPS is down at the nanosecond level. Alex "There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that "my ignorance is just as good as your knowledge." -- Isaac Asimov
Post #433,396 by pwhysall 4/5/20 5:25:57 AM 4/5/20 5:25:57 AM Reply	Having seen bespoke industrial software up close... ...I hypothesise that there is a fixed-sized data structure with a number of event slots or similar, that can hold 52 days worth of data, and which is supposed to be overwritten in a circular manner. Only the overwrite code is shit, so you end up with old data presented as current. This data structure is not persistent between powercycles, hence the instruction to turn the plane off and on again every 51 days. Or something.
Post #434,186 by CRConrad 5/27/20 7:54:25 AM 5/27/20 7:54:25 AM Reply	And it was originally planned as weeks, to hold a year's worth of data -- hence the 52? Either that, or they took it from the B-52.

Time for break from COVID-19... - (scoenye) - (6) - April 2, 2020, 05:55:07 PM EDT

I bet there is a 32 bit counter for time in milliseconds that is used to timestep events. - (a6l6e6x) - (5) - April 2, 2020, 10:52:18 PM EDT

That is the general thought - (scoenye) - (4) - April 4, 2020, 10:19:21 AM EDT

Someone did the math, suggested 40(?) bit microseconds - (drook) - (3) - April 4, 2020, 10:47:47 AM EDT

It must depend on what part of the many subsystems are monitored. - (a6l6e6x) - April 4, 2020, 09:59:20 PM EDT

Having seen bespoke industrial software up close... - (pwhysall) - (1) - April 5, 2020, 05:25:57 AM EDT

And it was originally planned as weeks, to hold a year's worth of data -- hence the 52? -NT - (CRConrad) - May 27, 2020, 07:54:25 AM EDT

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I'm picturing tablizer on a laptop dragging around a 486 whitebox running Linux attached to a really long extension cord.
43 ms