Re: xAP HS plugin errors

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

I'll have to leave the error messages to James but on the large number
of xAP messages I can help.

When you have a HS device (one that wasn't created from a xAP
origination) then you can choose whether this device should also appear
'reflected' out on the xAP network - this way all the inbuilt/plugin
devices within HS can actually become xAP devices - which is very nice
:-)      You can choose from the configuration pages on an individual
device basis whether this should happen. I am guessing that all your
HomeVision devices are also enabled as xAP.   HS has two xAP schema -
the 'HomeSeer' one and the BSC one which also means that if you use both
then you will get two messages per event.

Now BSC and the HomeSeer schema both send a message on change so if the
HomeVision plugin is repeatedly updating a device value (even though it
hasn't changed) then you will get xAP messages each time it does this.
That sounds like it would be the wrong thing for a plugin to do but
maybe there are other reasons they chose that approach, or maybe they
didn't anticipate this side effect,  there is another plugin that does
this too - is it DooMotion or something... What I would suggest is that
you disable xAP on all HS native devices that you aren't needing to be
accessible from the xAP network.  Of course you may want to leave
several devices xAP enabled this way as then you can use xAP Desktop or
xAP Floorplan (AJAX based realtime web interface) in place of HomeSeers'
inbuilt refresh based web pages to get nicer front end displays.

On the network traffic issue... a xAP message is a single UDP packet -
which means it has no protocol overhead in the IP layer (unlike TCP
where every packet is sequenced and acknowledged and there exists an
error/retry mechanism). This make xAP highly efficient but sacrifices
guaranteed delivery (just in case you were wondering it is possible to
bridge xAP using TCP rather than UDP for traversing the internet for
example with guaranteed delivery, and such an application is available
on the mi4 site). An Ethernet network can send a huge amount of traffic
per second - 10Mbs, 100Mbs or 1Gbs even  - a xAP packet is typically
only 150 bytes or so but at maximum occupies one Ethernet packet of 1500
bytes , say approx 15K bits with headers.   Based on the typical 100Mbs
Ethernet network...(and with a  lot of bad approximations along the
way)   100M/15K = 6.7K packets per second Which means a 100Mbs Ethernet
network could support traffic of over 6500 xAP messages per second....
quite a lot !

What does cause a hit though is the processing to generate these
messages and perhaps even more so the processing to receive them as they
have to be parsed - so on PC's running xAP applications you can get
performance spikes if you suddenly get huge numbers of xAP messages
coincidentally.  You might see this in HomeSeers CPU usage if all
devices change coincidentally and all are xAP enabled.  If you are
bridging a xAP network to a low speed network eg RS232/485 then there
are issues too.   In these circumstance with such hight traffic you
would generally pre filter messages, or even better not have such a high
volume in the first place.  High xAP traffic is almost never needed -
after all it is typically only generated on device state changes and how
many devices change state many times per second - and if they do is it
important to notify every change ?   In the BSC schema for LEVEL based
devices and with the Netiom for example when you have analogue to
digital converters they generate constantly changing values usually on
each sample (hundreds of times per second)  - but there is a user
configurable hysteresis setting such that they only report when
significant level changes occur. This can eliminate the small jitter
these devices create and reduce reporting to just useful changes for HA
purposes.

Cheers Kevin

PS I haven't used the HV plugin for HS but I might give it a try over
the w/e ..











Paul Gale wrote:
>
> I?m getting errors such as these occasionally ? few times a day:
>
> 01/07/2006 09:26:05  - xAP Conduit - HSEvent Error 64,[38,On,,,, Type
> mismatch
>
> 01/07/2006 09:26:05  - xAP Conduit - HSEvent Error 4,38,[,17,,, Type
> mismatch
>
> I have the HomeVision and a Comfort plugin working in the latest
> version of HomeSeer as well.
>
> Any idea what might be causing these?
>
> I?m also seeing a very large number of xAP messages ? generated by the
> xAp plugin from the HomeVision plugin  - it seems to refresh all the
> HV variables several times a minute, even if they?ve not been updated.
> Is this by design? Would a large number of xAP messages cause any
> problems or performance hits?
>
> Thanks,
>
> Paul.
>
>
>