Re: Re: Sensors / Switches / etc

["UKHA" <ukha@xxxxxxx>]

Hi Dan,

One of the things that you highlight is the single pair of wires used, from
this I've made the deduction that you are saying that the devices are daisy
chained off one another using a single cable. A number of potential
problems occur to me here:

1. If one device fails does the whole chain stop working?
2. The single point of failure for one 'room' is the CAT5 socket


>> 5. Devices don't require a PC (or other interfacing device) to
run.
>>
>As you have even a single PC in the home, then you dop not need another
>one.

Ahh, but the point is, your serial devices stop working if they have
nothing to talk to (eg PC Failure)
Ethernet devices still function, it is not inconceivable(sp) that you could
create a network of devices
that operate without the use of a PC using protocols like xAP and xPL or
even a custom protocol.

>There is any stand-alone home automation framework, network based,
which
>does not use a PC?
>

Not as far as I know, but for example somone *could* interface Homevision's
serial port with a Rabbit
and have devices talk directly to homevision, eliminating the PC entirely.

>
>> 6. I can't think of any more atm..
>Please try to convince me...:-))
>

Do I really need to? It sounds like you want to try anyway :D - The only
downside added is there is an
additional cost. There is no reason that you could not create your serial
devices, and then simply interface
the serial connection with a device like the Rabbit - instantly converting
your device (with a little programming)
to a networked one...


Go on, you know you want to... :D

Andy


*********** REPLY SEPARATOR  ***********

On 14/04/2003 at 14:43 Dan wrote:

>Hi Andy,
>
>Let me comment your answer too. To be short,  SWSB mean Single-wire
serial
>bus.
>
>> 1. Plug in and go when using DHCP, perhaps even automated updates
when
>using TFTP.
>You need IP address allocation only for ethernet, for serial a simple
swith
>is enough.. maybe something which can  be written in the device PIC
memory
>( no need for switches)... Online updating through TFTP can be an
>advantage,
>but on SWSB you can do it too, using some special sequences... if you
>really
>need it.
>
>>
>> 2. Any network socket can become a point on interation with your
Home
>Automation setup.
>>
>If  SWSB used, you can have unlimited number of serial devices on the
same
>RJ45 socket (using 2 spare wires), together with a PC. Is not nice?
>
>> 3. If you only have one CAT5 socket you can just hang a hub off it
and
>continue adding devices
>>
>Whit SWSB you can add as many devices as you want without the need for
a
>Hub, Switch or something else...
>
>> 4. because we can, and it is pretty kewl!
>I have no comment for this statement.... Is 100% correct!...:-)))
>
>>
>> 5. Devices don't require a PC (or other interfacing device) to
run.
>>
>As you have even a single PC in the home, then you dop not need another
>one.
>There is any stand-alone home automation framework, network based,
which
>does not use a PC?
>
>> 6. I can't think of any more atm..
>Please try to convince me...:-))
>
>
>Best regards,
>Dan
>
>P.S. I do not intend to make the apology of SWSB, but to better
understand
>the reasons behind network based home devices..
>