Re: Z-WAVE question

["Dean Roddey" <droddey@xxxxxxxxxxxxxxxx>]

All but a few of the newest Z-Wave modules don't send any type of
notifications at all, they must be polled. Obviously more than one
controller can poll them, but the bandwidth of Z-Wave would make that not so
great a thing to do, particularly if you want any kind of reasonably low
latency (which requires faster polling.) It would be optimal to only have
one thing in the system doing that polling.

I don't know how the Elk deals with Z-Wave, I control my Z-Wave system via
CQC. But they could certainly poll the network if they wanted to. CQC does
this, though if you have more than 10'ish modules then the latency will
start going up (or if any of the modules are having trouble communicating
that will also.) I have 6 modules currently, and the average latency is a
second or so, worst case is a few seconds (to see a change in a module
state.) CQC's Z-Wave driver keeps a few outstanding polling operations at a
time going, to reduce latency. This may or may not be optimal, but Zen-Sys
doesn't provide any guidance on these things, at least they don't to us,
despite numerous requests for such information.

Some of the newer devices, like the thermostat and some of the upcoming
motion sensors and such, will send out a notification when changed, which
will help. You still have to poll, to make sure that the modules are still
there and responding, but you can do it a lot slower since it's just a
sanity check and not used to maintain module status.

-------------------------------------
Dean Roddey
Chairman/CTO, Charmed Quark Systems
www.charmedquark.com

"Dennis" <djr-google.djrlar@xxxxxxxx> wrote in message
news:1145743253.307846.4220@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Two questions:
>
> I sent a message to the email address on the Z-WAVE site,
> (info@xxxxxxxxxx), and it was eventually returned as undeliverable.
> Are they still around?
>
> 2. According to the ELK documentation for their Z-WAVE interface,
> Z-WAVE modules report their status changes only to the unit making the
> change, thus HA systems like ELK can not know the current status of a
> device, thus can not use this information for automation control.  Has
> anyone heard of enhancements to the z-wave spec's to fix this problem?
>
> Dennis
>