Re: Device discovery for control/sensor schemas

["g8kmh" <lehane@xxxxxxxxxxxxxxxxxxx>]

Mal,
Agree 100%. The only comment I'd make is that legacy DMX is a bit of
a special case in that you don't get back status information. Any new
developments (such as xPL over 485 or CAN) would expect to present
back status/device list.

Lehane


--- In ukha_xpl@xxxxxxx, "Mal Lansell" <mlansell@f...>
wrote:
>
> --- In ukha_xpl@xxxxxxx, "John B"
<home-automation@j...>
> wrote:
> > Hi all,
> >
> > Many of the recent xPL apps are making use of the sensor/control
> schemas, as these make it much easier for devices to interoperate.
> >
> > However, there is no way of finding out a list of valid devices
> that a particular xPL connector supports.
> >
> > If we take DMX as an example, we can send a message like:
> >
> > control.basic
> > {
> > device=3
> > type=dmx
> > current=255
> > }
> >
> > This will set channel 3 to level 255.
> > But how do we know what channel 3 actually is?
> > Or even if channel 3 exists at all?
> >
>
> You can't.  Channel 3 will "exist" as far as a DMX
transmitter is
> concerned, but there is absolutely no way to tell if there is any
> hardware plugged in that responds to channel 3.
>
>
> > We should be able to be given a list of all known DMX channels,
and
> a friendly description of what is connected to them.
> >
> > The same issue applies to things like the C-Bus connector - you
> shouldn't have to remember the C-Bus group address of the light(s)
> you want to control - you should be able to be presented with a
list
> of all detected devices.
> >
> > The question is: Should each xPL connector be responsible for
> maintaining a list of "friendly" device names, and mapping
them to
> actual device names, so you'd be able to send something like:
> >
> > control.basic
> > {
> > device=lounge_lights
> > type=dmx
> > current=255
> > }
> >
> > Or should it be up to a controller like xPLHal to store this
> information and do the mapping between friendly devices and actual
> devices?
> >
>
> I don't think it's xPLHal's business to store such information,
> although it can help set it up.  Friendly device names should be
> presented as config items - but whether they are editable will
depend
> on the device itself.
>
> The mapping of name to hardware should be dealt with either by the
> xPL connector or by the device, depending on the abilities of that
> device.  The end result is the same - the connector/device combo
> presents friendly names to the xPL world.
>
> Take DMX as an example.  The channel names should be config items.
> In xPLHal, we can edit those names to best represent the actual
> device on the DMX network.  Scripts in xPLHal and messages sent to
> the xPL-DMX application use those names.  The application
translates
> the name to the channel and sets the appropriate light level.
>
> With more sophisticated hardware that uses such names already, the
> xPL connector would handle presenting those names as config items
to
> xPLHal, and passing back any changes.
>
> Mal