Re: Fw: How would YOU approach this HA task?

[Kevin Hawkins <yahoogroupskh@xxxxxxxxxxxxxx>]

On 29/10/2010 15:47, Paul Gordon wrote:
> Thanks Kevin. I think it shouldn't be too hard to maintain the onboard
timer
> programs... - the whole onboard timer unit is modular, and includes an
> on/off/timed selector switch, so it should hopefully be just a case of
> flicking *that* rather than an extra external switch.
Sounds ideal - I misunderstood when you said 'de-program'  thinking
that's what you literally intended ...
> The research I've done so far is giving me cause for serious concern
re the
> CBUS T-stat units...
I'm not sold either - which is why I've dithered for so long...
> - They are configured to operate on the HVAC application, although it
does
> seem to be possible to change that to the lighting application
(otherwise
> I'd not have been able to "share" an existing relay module
that I just
> happen to have 1 spare channel on)
Yes although I think the functionality isn't impaired at all as they
basically use the same C-Bus protocols as lighting (unlike some other
C-Bus apps).
> - I'm not sure it's possible (still trying to find out) to adjust the
> setpoint temperature remotely from other CBUS units - if so this is a
> *major* shortcoming
Let me know what you find - if all you can do is override the timer I
too feel it's a limitation
> - although it broadcasts the actual measured temperature on CBUS, it's
not
> entirely clear how useable that actually turns out to be for use in
other
> units...
On the measurement app it's probably fairly easy to utilise elsewhere
but probably not on the lighting app. I don't believe Comfort can access
the C-Bus heating app but I could be wrong.   From Wiser though you
might be better served.  I haven't played with Wiser programming too
much but from a touchscreen you can get the temps into system variables
and then use them as you wish (would have to check re this if using a
lighting app).  There are several lighting app ID's you can use so you
don't literally have to share the 56 (x38) app.
> - Worst of all, the forums are littered with dire warnings of the four
> horses of the apocalypse descending to destroy the Earth if you even
*think*
> about letting anything else other that the CBUS T-stat switch that
relay
> channel controlling the boiler... - this is an absolute showstopper if
> true...
>
Well - I am not sure quite how vital this really is but you never
know... A way around it would be to connect yet another relay(s) in the
circuit that offered manual control.   A parallel relay allowing you to
override (turn on) the heat demand even if the thermostat had it off,
and a series to do the reverse.  You may not need the latter control
though.  The thermostat would still always think it was in control of
course.   You might even be able to save those extra relays by allowing
the thermostat to control one of the available 'logic' groups within an
output unit and then synching the logic group with your relay using
logic.  Again the thermostat would remain happy as it's control group
would always be 'untouched' by external interaction. .  A logic group
(and not just  a non existent 'virtual' group) would be required as they
are fully maintained status wise by the C-Bus hardware.
> More research still required, but following my initial optimism
regarding
> these units, I'm now beginning to think that they might be a big fat
waste
> of time..
Ben A I think has some experience of these - maybe he'll chirp in.
Let me know what you find out  as I'm considering much the same    Don't
want to be the first mouse...

"The early bird catches the worm but the second mouse gets the
cheese"

K
> Paul G.
>
>



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