> Topic tags:[Arch][Wiring][Doc][HW][PM]
> _______________________________________________
>
>
> >I am assuming that they have none. The devices that provide the
> UI need to
> >be able to communicate directly and simply with the Embedlets. Envision a
> >plant operator walking up to a device with his wireless or wired
> hand-held
> >to make adjustments to the system. Requiring JMX as the sole management
> >interface would, I think, put a very large infrastructure demand on that
> >simple interaction. It would also lock out other socket/XML capable
> >interfaces such as ActiveX (yes it still lives), .NET, Perl etc. I agree
> >that a JMX/Embedlet Adapter would defintely be a huge boost to the
> >acceptablility at the Enterprise management level.
>
> The MBean would not necessarily have to be on the device. If we
> spec a very
> simple text based admin protocol that provides 'events', 'properties' and
> 'actions', then we can write a single MBean that can run on the managers
> device, and talk via a serial network to the device. If you then
> make that
> protocol implementable as a Jini Surrogate implementation, then
> you could also
> use Jini's discovery mechanisms to allow embedlets to announce
> their presence.
> This would facilitate remote management in places where device
> have a network
> to somewhere else.... But a serial port could be used for management of
> individual devices.
> -----
> gr...@cy... (Cyte Technologies Inc)
>
This is what I am advocating. The text based admin protocol would be a terse
XML form since it would not make sense to reinvent that wheel. I have found
that if XML elements are use to enclose objects and attributes are used to
define properties it can be very compact.
For example a request:
<Request command="getProperties" identity="CB_OUTPUT_1"/>
The response:
<Light identity="CB_OUTPUT_1" name="Light 30212" value="On" .../>
This can easily be handled by one of the small-footprint parsers or a
hand-rolled byte level parser. It is in stripped XML form so that an upper
level transport can simply enclose it into a full envelope or transform it
to established protocols. Collections, compound objects and reference links
are possible using this technique as well.
<Lights identity="LIGHT_COLLECTION_01"
class="org.embedlets.PersistentCollection">
<Light identity="CB_OUTPUT_1" class="com.myCompany.GPIOOutputPin"
name="Light 30212" ...>
<EventSource href="SWITCH_992"/>
</Light>
</Lights>
This becomes the foundation for building complex systems out of very simple
rules, as Andrzej has proposed.
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