Re: CBUS problem, can I bounce an idea off you...

[Stuart Poulton <stuart@xxxxxxxxxxxxxx>]

Paul,

The not a cbus owner, but the following is interesting reading

http://www3.clipsal.com/cis/pdf_files/Inside_C-Bus.pdf

In particular section 6.8 onwards

Stuart

On 25 Sep 2012, at 20:17, Paul Gordon wrote:

> Chaps, hoping some CBUS users out there might be able to help me keep
> (what's left of) my sanity. - and restore my faith in the absolute
> rock-solid reliability of CBUS kit!
>
> Over the last couple of weeks, I've noticed increasing unreliability
with my
> CBUS install.. At first it was quite rare, the very first problem
happened
> about a month ago, but as time has passed it has become more and more
> frequent, and it's been driving me nuts.
>
> In a nutshell, almost every one of my output units intermittently
fails
> completely. meaning I cannot switch any lights or appliances on that
module
> on or off.
>
> Most of my output units include a power supply, so my initial thought
of a
> network power issue seemed unlikely. When the problem occurs, neither
the
> CBUS or UNIT led's are on, and the local channel override buttons on
the
> unit do not function - for all intents and purposes the unit appears
> completely dead. But the thing is if I scan the network with CBUS
Toolkit,
> the unit appears, and reports its CBUS voltage (30.2V in this case.) -
and
> yet NOTHING is working. - I'm looking at one right now. physically it
is
> dead, but it is talking to toolkit.
>
> On all occasions when this occurs, it seems to just
"magically" fix itself
> after some period of time, which can be anything from minutes to
hours.
>
> I have just started to formulate a theory, based on a few
observations.
>
> CBUS Toolkit is not showing the Line/Mains Present indicator for the
units
> that are currently "dead".
>
> I just measured the mains voltage supply at the input to the module..
- its
> currently reading a mere 196VAC on my multimeter.
>
> The local power supplier has had the mains off in the area for several
hours
> today, - following a letter I received about a week ago informing me
it
> would be off today for essential repair work following problems in the
area.
>
> Now it all starts to make sense.
>
> All this time I've been tearing my hair out because of the
intermittent and
> sporadic nature of the behaviour. - that pretty much seemed to
logically
> rule out most types of hardware and/or cabling failure. - although
that
> hasn't stopped me crawling around the attic/cellar etc. trying to find
a
> break in the CBUS network cable (I thought maybe a mouse was chewing
through
> it somewhere) - but the fact the none of the input units *ever* had a
> problem confused me even more with the theory of a CBUS network
problem.
>
> I think the fact that my problems only started about a month ago, and
the
> letter from the leccy co can't be coincidental. - I'm thinking there
must
> have started to be a low voltage condition on and off. - based on
local
> demand perhaps? - the problems always seemed to be worse in the
evening.
>
> Also adding to the confusion, is that if I'm right, and this *IS*
caused by
> my mains supply being undervoltage, - absolutely nothing else
electrical in
> the house has exhibited any kind of problem at all. - it's
exclusively, and
> only CBUS output units that don't like it.
>
> Looking at the manual for the units, it does specify supply voltage
220-240V
> - Mine is currently well under.
>
> So my question is this. - on the CBUS units *with* power supply, I'm
> guessing it must be true that the CBUS circuitry in that unit can
still
> function on CBUS network power coming from other powered units.. -
even if
> the unit isn't on the mains itself. - my observations suggest this is
true.
> - which is why it still talks to toolkit, as some other units in
different
> parts of the house are still "alive" and supplying CBUS
network power.
>
> Does anyone know if the CBUS output units really *are* that sensitive
to
> variations in mains supply? - and if so, might it be true that units
without
> a CBUS power supply are LESS sensitive? - because it seems to be the
case
> that I've never had a problem with a couple of units that lack a PSU.
> (although they are closer to the incoming mains well, so that may be
the
> reason).
>
> Off to complain to the local leccy company methinks!
>
> If you got this far.. Thanks for listening!
>
> Paul G.
>
> [Non-text portions of this message have been removed]
>
>



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