Acceptable Practices: Sharing sensors (was Re: X10 still around?)

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Marc F Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote

<stuff snipped>

> I have a change-over question. Is it 'acceptable' practice to have two
> systems on the same sensor? There are EOL resistors on most everything.

The FAA, FWIW, says no.  There was a crash of an airline in South America
because two independent sensor systems shared the same faulty sensor.  They
issue a mandatory redesign of the system.

I'd say if you defined your system as "should *never* fail" then you
shouldn't share sensors.  It would be handy if that premise also came with a
magical elf that could install all the duplicate sensors and pay for them,
too!

I've designed my CCTV and alarm systems with substantial overlap in sensor
and camera coverage.  More cost and more wire to run and sensors to install,
but more peace of mind in the long run.  More protection from sensor and
camera failure, too.  Not 100% overlap, but the critical areas all are
double and even triple-covered.

--
Bobby G.