RE: Hello All! I'm looking for advice!

["Phil Harris" <phil@xxxxxxxxxxx>]

> -----Original Message-----
> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of
> Paul Gordon
> Sent: 15 January 2007 15:54
> To: UKHA_D Group
> Subject: RE: [ukha_d] Hello All! I'm looking for advice!

<<SNIP>>

> How many burdens you need depends on your CBUS network design. Suffice
it
> to say that you need at least 1. I rather suspect that an
"average" UK
> size house probably won't need more than 1 however...

Sorry Paul - just gotta make sure this is corrected...

There should be no more (and no less) than one burden on any one C-Bus
network. The burden may be either a plug-in physical burden or a software
burden enabled on a C-Bus device such as a PC Interface, Network Interface,
Dimmer, PAC etc.

There should never be a requirement to have more than one burden on a
network and if for some reason you do find that you need more than one
burden to get a network stable then you should look at the network itself
more carefully to see what is wrong as there will be something else that is
putting the network out of spec (too many power supplies for example -
ther=
e
is a 2,000mA limit on a single network - or perhaps the network is
physically too long - there is a 1000m limit on a single network).

If you need to go over 1000m (or if for some reason you have to have more
than 2,000mA of power supplies) then you should split networks using a
network bridge. In this case each side of the bridge is regarded as its own
network and each will need a burden.

> I'm not aware of any particular special Clipsal terminal block for
CBUS,
> but it wouldn't surprise me if there was (as you say, for =A3100 of
> course!),

Cheeky sod! :-P (And no - there isn't.)

> however, like I already mentioned, any common terminating method
> is acceptable as long as the termination is good.

The actual C-Bus network itself is very rugged as far as data comms is
concerned (I have seen some very interesting installations across some very
not-at-all-CAT5e cabling) and they still worked absolutely reliably.

The previously mentioned "commoned RJ45 patch panel" solution
would be
perfectly fine if you wish to do that however it's probably more
"aesthetically pleasing" than physically necessary - it looks
more
impressive when you open up a panel and say "This is where all my
light
switches terminate back to" but apart from that probably not a huge
advantage.

Something like a punch down Krone termination block would also do the job
perfectly well. However, allowing for the real world where we all have the
best of intentions that a proper and tidy job will be made of installations
then when you're hanging upside down in a loft and you just want to get the
thing finished and get to bed / get a beer / watch the footie then good old
fashioned "chocolate blocks" will also do the job (just be
careful when you
screw down the terminals that the twisting of the screw doesn't break the
CAT5e conductors).

Remember when you're running cables to/from switches you are only using
fou=
r
cores of the eight that are in CAT5 cable and of those four cores you are
using them as two pairs solid / solid + stripe / stripe for C-Bus positive
and C-Bus negative respectively.

Phil