In message - "Simon Robbins"
writes:

"David Harper" wrote in message
. com...
Does the C-130 have two 1553 buses onboard? One for flight control
and one for EW/mission systems?

I don't think 1553 is used for flight control since the latency and speed
isn't sufficient. Mission systems may well use it though. I think by nature
1553 is dual-redundant so that's where you might get the idea of two from.
Not familiar with the C-130 personally though.

Si



In flight control systems tolerable delays are so large by todays computers
standards than it's hardly an issue: for example, such an agile fighter as
F-16 feels OK with about 1/2 second delay between the stick input and control
surface movement. The fastest type of signal is stabilization augmentation -
the control surface can oscilate at frequencies from somewhat below 8Hz in
F-4E to something like 20Hz in F-15 (not having F-15 experience the last
figure is taken from someone else's words). A delay of the order of 0.1 sec
is HUGE by even a modest computer network standard. I don't remember by heart
the 1553 standard but I'm sure 0.1 sec delay is well within limits.

BTW, one of the replys was dealing with 1553 throughput in B-2. Please note
that throughput and delay are not the same and quite often they're
contradictory desigh trends: a design optimized for min. delay will have
lower throughput and vise virsa (assuming same cost). So, measuring a
throughput from one network point to another is irrelevant to FLCS tolerable
delay. What should be measured is the worst case max. delay, usually at top
throughput and in some particular "pathologic" case of network traffic.



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