(long reply from Phil) RE: Manual control of LD10/11 was RE: Conventions...

["Phil Harris" <phillip.harris1@xxxxxxx>]

> Why not wire these buttons back to HomeVision Phil ?

Simply because I don't want to be reliant upon HV for control ... being
able
to remove the stuff (HomeVision) from the equation and have the house
return
fairly much to normal is important to me.

I can see your point and Keiths too and I must say that it would be nice to
have a switch panel which had an on/off control that did just do on and off
plus separate Brighten & Dim buttons. If it was possible to get
something
like an LW10 wall switch (but one that that didn't look like a dogs dinner
after it has been eaten and vomited back up) that had separate buttons for
Dim/Bright but had no switching functionality and only broadcast the X10
commands onto the house wiring then I would certainly consider such a unit
-
especially since HV would then be able to track the light level - however
having the centralised and specialised control of core house functionality
that would come along with routing all commands and switching through
HomeVision is unnaccaptable to me. Evaluate the risks and ditribute then
accordingly!

If I have a rack of LD10/11s and Clipsal switches then say we sold the
house
I can either leave the lights on the LD10s as dimmers and know that the new
owner will be able to source a new LD10 if anything goes wrong and any
sparks capable of holding a screwdriver by teh right end will be able to
change them (they're not difficult to get hold of) or I can replace the
Clipsal switches with the original switches and remove the LD10s easily and
have the lights revert back to simple on/off use as normal.

Take for example the group project ... Now, I do not want any of the guys
working on this project to take this as any slur on their abilities and I
can see the attraction of what they are doing but to me this lighting
control system is unnacceptably "risky" ... it's a closed and
proprietry
system which will require the continued input of the developers to
maintain.
What happens in five or ten years time when a triac blows? At best we will
probably end up having to dismantle the unit, find the fault and replace
the
triac (or other component) ourselves (it's unlikely that in five years time
any of the guys will have stocks of spare built PCB's ready and waiting to
send out for next day delivery) ... at worst we'll have sold the house with
the lighting system integrated into it, the new owner will have tried
replacing a bulb, got frustrated and had to call out an electrician. The
electrician will turn up and then tell the owner that he has no idea what's
going on with this system as it's something he's never seen before, there's
nothing he can do to fix it and all he can suggest is rewiring (as he'll
not
know whether the system is capable of being reverted to normal or not).
Now,
I have great respect for what the guys are doing on this project and the
hardware design and firmware logic will need - and show - a good level of
skills but surely far more usefull would have been a small PCB capable of
fitting into a single UK backbox that can send out ON/OFF/BIGHTEN/DIM
commands for a single house and unit code upon the closing of a couple of
switch contacts? Then a couple of switches in Clipsal plates could be used
(or you could build up your own front panel) and you'd have a nice looking
and really functional wall light switch. (I know this is kinda covered by
the Leviton scene controllers but they're overkill for this task.)

I was having this discussion with John Hill the other night about how
embedded into the infrastructure of the house I wanted the home control to
go and for me I don't want it too deeply integrated. *ANY* piece of
hardware
increases the chance of failure in a system and even though HomeVision is
reliable it isn't perfect and can die/crash. If I'm not relying on
HomeVision to supply the intelligence for the basic "hit the switch on
the
wall" functionality then that's a good backup as far as I'm concerned.

For the curtains then the simple toggle is fine for a "beside the
door"
control.

Now ... where HomeVision does come in as far as I'm concerned is *ADDING*
functionality to this arrangement. To this "basic" hardware only
system I
can then have Homevision adding a lot of extras.

The K400 motors for the Swish rails have three control lines - force open,
force closed and toggle state. Wiring the "toggle state" line to
the wall
switch and the force open/force closed lines back to HomeVision allows
local
control of the curtains within the bedroom as well as allowing HomeVision
to
make the place look lived in when we're out or have remote control of the
curtains from a Pronto (where, if you do want to control the curtains in
another part of the house, I would usually want to force them open or
closed
not toggle their state).

It also can control the LD10s directly so that I can say have a single
command to HomeVision which effectively says "We're going out ... you
make
the place look lived in" and then HomeVision can do its stuff and have
curtains closing *BEFORE* putting lights on, turning lights off at
appropriate times and in appropriate orders, opening curtains in the
morning
etc. I see nothing as silly as using timeswitches or timers to switch
lights
on and off when leaving curtains permanently open or closed - obvious
advert
that a house is unnattended!

The *ONLY* room in the house where I will have more than one lighting
circuit is in the AV Room when I do it. In that room I am prepared to let
HV
have more of an active role because that will be *MY* room - if something
doesn't work then it's not too much of an issue. The rest of the house has
to be able to be "run" by Jo or Edward and if I'm out for a
couple of days
(as I often am) then Jo is not going to stand waiting for me to return to
sort out a bug in a HomeVision schedule. (And she shouldn't be expected
to.)
What happens if - say - HomeVision has a problem which causes Edwards
bedroom light not to work, Edward gets up in the night and wants to turn
the
light on, it doesn't work. He's going to panic and then get himself wound
up
and scared and end up in tears ... five year olds don't listen to you
saying
that someone has accidentally unplugged the TW7223 or there's a bug in your
schedule let alone wait for you to correct it. If something that used to
work suddenly doesn't then it is a big issue ... anyone who has kids surely
must understand that?

Phil



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