RE: C-BUS vs. EIB

["Hawes,Timothy Edward (GEG)" <haweste@xxxxxxxxxxxxxxx>]

> -----Original Message-----
> From: Neil Ball  Sent: 11 March 2004 16:11
>
> Hi Tim
>
> I think you're confusing EIB with the Siemens product range.

Quite possibly :-)
Also see the disclaimer at the end.

> Unlike C-Bus
> which is Clipsal's proprietary network protocol, EIB is an
> open standard
> that while developed by Siemens is licensed to other
> companies e.g. you can
> buy a complete EIB control system from ABB and others - this
> is manufacturer
> used by the chap on Grand Designs who was shown earlier in
> the series - The
> Return to Cloud 8.

But, IIRC, he has also set himself up as an Integrator and no doubt he paid
a substantial sum to do that. From what I read on his site, his intention
is to offer intelligent BMS after he's completed his build so could justify
the outlay as a business expense, at least notionally, if not actually.

> It may well be that the Siemens EIB implementation adds
> private extensions
> to the public protocol thereby preventing full
> interoperability with other
> systems and preventing 3rd party software tools from being
> used. This is
> mostly the case with other open standards within the controls
> industry e.g.
> Lonworks.
>
> You are correct over the commissioning issues - Siemens only sell the
> software tools and training to approved integrators which are
> still pretty
> thin on the ground at the moment.

I'm not quite sure I follow you now. You say I could buy a system from ABB
for e.g. *but* I would then need ABB to come an commission it because
Siemens won't sell me the software so I can do it myself. I can see the
subtle difference between what I said & what you said but we end up at
the same place don't we ? i.e. *no DIY*

> Then again, in some areas
> this is no bad
> thing. How many would be able to develop and write suitable
> HVAC control
> strategies for heating & cooling plant and be able to include
> all of the
> necessary safety interlocks, multi-stage frost protection etc
> that these
> more complex control systems offer.

Well my day job is specifying PLC systems & writing code to control
industrial process plant, but I see where you're coming from ;-)

Although equally, how much of this is required in a domestic environment ?
If you took a regular boiler and, instead of a normal wall thermostat, used
an EIB-compatible temperature transmitter and some EIB dig outputs, you can
repeat the functionality of the normal domestic system, but then do much
more. Night set-back, time-of-day on/off, dial in for remote setpoint
adjustment or heating advance etc. Nothing particularly earth shattering
there, and in many respects, what guys here are already doing by other
means. I don't know CBus, but I would guess you could do something very
similar with that system too.

Maybe you don't get the full benefit of EIB if you don't use an EIB boiler
but does it matter ? do they even exist in domestic sizes ? -  What extra
functionality do you need that the above example configuration can't
provide ?

> Most of these systems only offer
> programmable I/O which requires someone to design, write and
> test the code,
> which is why the manufacturers only use approved integrators
> most of the
> time.

Much like a PLC. And CBus. And HomeVision. Like anything, you could argue
that if you're going to buy a system with the intent of programming it
yourself, you might check whether you actually have the skills to do it, or
book yourself on a course. The fact that EIB can be scaled up for very
large commercial projects I don't think is relevant. If EIB is to be
offered to the domestic market, the pricing and functionality (including
the ability to make modifications) has to reflect that or it won't sell.

I can buy an Allen Bradley PLC from RS. They don't care whether I have the
skills to program it - that's my lookout :-)

> Mind you in the case of Siemens I cannot comment on how
> much HVAC
> knowledge their integrators actually have.

Pass, but does that matter for many (the majority ?) of domestic systems ?

> If you do not need to use analogue sensors or control
> equipment and only
> need a digital control system (i.e. VFC in/ relay out) then
> take a look at
> the Square-D system.

Thanks for the pointer, I'll check it out :-)

No analogue input sensors can be a significant drawback - take my boiler
example above. You can always approximate analogue via multiple digital
switches, but that's not a very elegant solution (both from a code POV, and
an aesthetic one - wall acne), it's a pain to configure and uses up
valuable I/O.

Temperature is the obvious requirement for analogue, but what about
measuring light levels too, and flowrates ?

> It is much more basic, but the
> interactive training
> course can be found from their web site. They seem to be
> trying to recruit
> electrical contractors to do the install/commissioning so I'm
> sure they will
> also sell direct to suitably qualified end users as well.

It will be interesting to see how they define "qualified". But
IMHO, that's a good approach for us here on UKHA.

Thanks for your comments - I think it's prompted an interesting discussion
:-)

> Neil B.

Cheers,

Tim H.

Disclaimer:
I've no personal preference for any of the systems mentioned above and I
have no personal commercial connection with Siemens although my company has
a supply agreement with Siemens (amongst others) for PLCs and industrial
controllers.


> -----Original Message-----
> From: Hawes,Timothy Edward (GEG) [mailto:haweste@xxxxxxx]
> Sent: Thursday, March 11, 2004 12:45
> To: ukha_d@xxxxxxx
> Subject: RE: [ukha_d] C-BUS vs. EIB
>
>
> > -----Original Message-----
> > From: Mark Kaye  Sent: 11 March 2004 11:26
> >
> > I'm just trying to throw the pros and cons of these two
> > together and see
> > what comes out of the mix.  Bearing in mind I'd like to
> combine these
> > with Comfort and try to avoid X10 if possible, does anyone have
any
> > opinions on the two standards?  Any help or views would be much
> > appreciated.
>
> Mark,
>
> One big difference between the two systems is that one *is*
> DIY-able and one
> isn't. At present in the UK, EIB can only be installed(1) by
> one of only
> three "Partner" companies. This may change in the future,
but
> that's the
> current situation.
>
> Note 1: AIUI you can do all of the first fix work yourself
> (pulling cables)
> etc, but one of the Partner Co's has to come and connect &
> commission for
> you.
>
>
> With C-Bus, OTOH, you can pay about 400 quid or so, take a
> course and then
> walk away with about 400 quid's worth of hardware to start you off.
>
> From a technical standpoint and without having personal experience of
> either, I'd say that you could do pretty much anything you
> would want with
> either system.
>
> Tossing another supplier into the ring - have you looked at Polaron ?
> http://www.polaron-group.co.uk/controls/
then click on
> "Polaron Building
> Systems". This is also a very competent system, and one that
> can integrate
> with the QED whole house audio products, right down to using common
> faceplates.
>
> HTH,
>
> Tim.

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