On Feb 4, 7:39 am, "G.T" <g...@[EMAIL PROTECTED]
> wrote:
> Hi,
>
> > The window could still be wound up, well maybe after a delay, so
whatever
> > the problem it wasn't fatal
>
> This time, for you it wasn't fatal. Sometimes it really was nightmares
(esp.
> on 307s).
>
> > Also I don' understand why window switches need to be multiplexed, it
> seems
> > to add an unnecessary complication but then I am no electronics
expert.
>
> OK, I'll give my point here.
> Multiplexing (muxing in electronics slang) was bought into automotive
> industry to reach two goals : one was the amount of wiring needed for
the
> car (a 405-class had something like 6km - 4 miles), the other being the
> invasion of electronis (most of them wanted by the customer himself,
> commonly called "comfort features") and for a better interaction between
the
> car elements (engine ECU & peripherals for example) - think "pollution
> reduction".
> So here we are : comfort and cost reduction.
>
> The muxing is (I should write "was" as we could consider it like oldie
now,
> first muxed cars at PSA's being the XM and the 605 - on a lighter
> integration though) extactly like the relays-to-automates revolution in
> industrial installations : replacing the horrible number of relays by
only
> one automate (Industrial Programmable Automates ?) and a couple of
relays.
> So we encountered the same nightmare stories due to some hardware and /
or
> software design issues, exactly the same way. Happily, most of issues
were
> only software-related at PSA (I except the first 307s and Picasso's
where
> the BSI itself was subject to some water getting inside).
>
> Errr, I hope it remains easy to understand.
>
> Regards,
> --
> G.T
This 'fly by wire' multiplexing thing is taking over the world and we
have a long way to go. Cars have, for years, been using it. Homes use
it. Boeing 747s use it. In fact my impression is that it started in
aircraft.
The idea that you can send instructions to odd bits of hardware around
the vehicle/premises is great. But if the receiving hardware has a
glitch you get things like windows opening and closing for no apparent
reason etc.
Presumably the receiving hardware becomes more sophisticated over time
so that it can identify and correct or ignore nonsense instructions.
But it is frightening that, for instance, my first two peugeots - a
504 and a 505 were totally devoid of all this stuff and engine
management systems. I understood every detail of the vehicle's
operation. No more. Sad!!!
I must admit that the 406 I have owned for the last nine year and the
407 I test-drove today are singularly pleasant - user-friendly -
comfortable vehicles. And the 406 has only failed to operate about
three times in nine years (and came good without any expert
intervention). But, having, for most of my driving life, had a fairly
complete understanding of what my vehicles were doing (and the
ability, in most cases, to diagnose and fix any failures), the current
world where I am, instead, driving a sealed 'black box' is, when I
think about it, terrifying.
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