Re: Fw: CBUS & Comfort Questions

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

Hi Chris ,

This posts already a bit messed up reply indentation wise but I hope
you get the gist .... I don't actually use Comfort but applying what
I've learned elsewhere I've added some guesses...on how I expect it
might work

Gareth Cook wrote:
> Hi,
> I'm about to start a cbus & comfort install in my house and I've
got a
> few questions for you clever people.
>
> How closely integrated can you get cbus & comfort. For instance
for my
> lighting setup I need a 12 channel cbus relay costing around
£520. If I
> have a ucmcbus module in the comfort box can I replace the cbus relay
> with comfort 240v relays, 12 x £28 = £336, thus saving
£194 to pay for a
> free ucmcbus?
> Yes, but you are limited by the number of total comfort outputs - not
so
> with cbus.
>
Also - any Comfort outputs do not become correctly represented on C-Bus
as they don't exit there - ie they don't correspond to a true C-Bus
group and therefore don't correctly report status using MMI  on C-Bus,
they can be controlled from C-Bus though.
> Will I be able to get exactly the same performance using comfort
relays
> for lights? Will CBUS scenes work in the same way switching lights
> through comfort? I'll still need cbus dimmers, the relays are just for
> external lights and utility areas.
> Yes - using 12v <> 240v relays of course - a few quid. I have
some CBUS
> buttons activate comfort relays, and also cbus buttons tell comfort to
> activate cbus channels (ie pressing the same light switch when it's
dark -
> will only turn the light on to 50% without holding for dim)
>
I think by 'scenes' you mean groups in this question - otherwise the
next Q is the same isn't it ?  This I think works although C-Bus will
not correctly report the states of the outputs present on Comfort - it
will see and report them as 'absent' but you can control them ok.
>
>
> I will be using scenes in cbus so can comfort relays be a part of a
cbus
> scene, having a cbus switch trigger a scene containing cbus dimmers
and
> comfort relays?
> Not directly, but comfort could activate a comfort output and then
tell a
> cbus channel to activate.
>

If you have a scene and divide outputs between C-Bus and Comfort then
(as before) those outputs on Comfort will not maintain correct 'group'
status on C-Bus and as such you won't be able to use the feature where
key indicator lamps remain lit when scenes are valid and go out if
broken ( a member changes state) - but this feature isn't too dependable
anyway and wouldn't be a great loss.
>
> Whilst on the subject of scenes, is it possible to dim scenes? If I
have
> a 2 button switch with a scene on each switch would it be possible to
> turn a scene on with a button press and then dim the whole scene up
and
> down with press&hold on the switch? Or is dimming only possible on
> individual lights?
> I think so !
>
Not sure if G is saying yes to 'only individual lights' here or your
wanted dimming ?? AFAIK it is not possible to dim scenes  - however you
can assign an area to a dimmer pack (and dimmer switches too I think)
which allows you to dim all the area as one ie all channels on one , or
several dimmers. You can also put the same group on several dimmer
channels  too but then they are really just one bigger channel, you
can't control them independently.  To do what you want I think you need
more 'smarts' eg something that will link several different groups to
one as a master dimmer. This could be done with a PAC or C-Bus
touchscreen or xAP/xPL.  It is possible you may even be able to program
Comfort to handle this too - it would take a required dim level and then
instruct each dimmer channel (C-Bus Group)  individually (sequentially)
to go to that level .   The result would still appear to be one
co-ordinated dim , especially over longer ramp times.
> I'm just specing the system out, so I'm sure I'll have more questions
> once I get going.
> Thanks,
> Chris
>
Scenes on C-Bus are not 'collections of dimmer channels' - they are a
collection of dimmer channels each member of which has a defined final
dim level at a specific ramp rate. They are 'triggered' by setting a
certain trigger/action pairing, So as such members of scenes can't be
dimmed as one. without a little 'programming' help.  Achieving complex
multifunction (shortpress longpress) scene control is quite awkward on
C-Bus switches due to trigger group membership issues,  but you can also
use standard groups with suitable smarts 'PAC/Touchscreen/xAP'  to do
the same thing - if not more.    Comfort relay outputs will not maintain
correct status on C-Bus so you will need to take care with any C-Bus
'logic' programming that depends on knowing the state of such outputs.
eg "If outside floodlights are ON then do this..... (where outside
floods are a Comfort output)

Kevin