Configuration process

[Keith Doxey]

Hi All,

Apologies if this was covered in the xAP group but even if it was, it could
well be different here!

Taking the example in the xPL spec of the Temperature Sensor installed in
the garage.

I'm OK with the message it sends out requesting a new config but heres
where
I get stuck....

"The management station notices a config message and logs it for the
attention of the automator. The automator assigns a sensible name"

MYHOUSE then targets a message at Vendor.Device.DEFAULT

What happens if several similar devices have been plugged in ?
They are all the same type and request a new config and are looking for a
message targetted at themselves with an instance of DEFAULT. All would now
be called GARAGE.

Having to go back to the console everytime a device was installed would be
tiresome to say the least.

Assuming the INSTANCE can be changed at will, would it be a sensible idea
for the House Manager to assign a temporary INSTANCE that was either the
primary key for the database entry in its log (assuming database exists) or
a timestamp of YYYYMMDDHHMMSS ( 14 characters so permissible in length) as
an acknowledgement of the request.

When the automator then goes to the console each new device would have a
timestamped entry and would have had its default instance replaced by a
uniquely addressable one (assuming you werent super human and plugged in
devices at a rate of more than 1 per second!) for assigning the friendly
name.

Presumably each device would have to have some form of non-volatile memory
such as EEPROM to store its config otherwise it would need to be
re-addressed after each power failure.

Also, devices would need to be "hot pluggable" otherwise if you
connected up
18 PIR's and then wacked the power on, all 18 would demand an identity at
the same time and even if some form of psuedo-random powerup delay ensured
that the majority of requests got through you would have no idea which was
which.

With HOT PLUG you would know that you did them in the order

Lounge_South
Lounge_North
Hall_Narrow
Hall_Wide
Kitchen
Diner
Bed1
Bed2
Bed3
Bathroom
Study
etc...

therefore the logged entries could be assigned their true names.

One further point that I dont specifically see mentioned in the spec are
the
delimiters identification. I am assuming that because the fields are not
fixed length but length limited that "-" delimits VENDOR-DEVICE
and "."
delimits DEVICE.INSTANCE is this correct.

Also is white space banned/ignored unless it falls between "="
and <CR> in a
name/value pair as per xAP.

Once again, apologies if much of this has already been covered but I have
missed quite a lot!

Makes interesting reading :-)

Keith

www.diyha.co.uk
www.kat5.tv