Re: Wil I be able to use a Z-Wave controller

[nobody@xxxxxxxxxxxx (Dave Houston)]

Neil Cherry <njc@xxxxxxxxxxx> wrote:

>On Fri, 12 Oct 2007 13:11:11 GMT, Dave Houston wrote:
>> Neil Cherry <njc@xxxxxxxxxxx> wrote:
>>
>>>Jason Sharpee also found this:
>>>
>>>http://www.leviton.com/OA_HTML/ibeCCtpSctDspRte.jsp?section=22201&minisite=10024
>>
>> Thanks for that URL. The PDF "Specifying a Vizia RF system" says
>> more-or-less the same things I've been saying for a few years (since Z-Wave
>> was introduced). They say you need a node every 30' "typically" while I've
>> said 20-25' for reliability, especially in in an unfriendly RF environment.
>
>This seems reasonable for whole house automation (one every 25 ft) as
>it would be one in every room. But for the Christmas lights folks they
>may have some trouble. My computer is on the far side and the displays
>would be towards to front of my home.

A couple of their dealers were claiming wildly inflated range figures. One
even claimed Zensys used super-secret technology that gave ultra-long range
even through metal. ;)

Be careful of the max hops issue. The standard systems are limited to 4 hops
which may be inadequate from the "far side" or beyond. Leviton's high priced
spread has 7 hops which should be adequate but whether a non-Vizia remote
can iniate longer-lived signals is a question you should look into.

>One thing I found out is that in addition the the device module you
>must have a Master (Leviton calls it a Primary) Remote to group the
>devices. The RS232 interface is not a master device. So I now need to
>get a Remote. I intend to go cheap and not get the nice Leviton unit
>but one of the other ugly units. The RS232 documentation suggests it
>should work. I've found one for about $45. I'll find out later if
>Z-Wave will operate without the Remote once the group has been setup.
>
>PS, pardon the terminology, I'm not up to speed on the correct terms
>fo Z-Wave.

I'm not up to speed either. I looked at it early on and decided it was too
limited so have only checked on it sporadically as others have asked
questions (which has been infrequent). I noted the Echelon white paper which
spoke to the range issue way back when.

http://www.echelon.com/support/documentation/documents/005-0171A_RF_White_Paper.pdf

There were issues with secondary controllers being unaware of events for
which they were not the master and there were issues with the necessity to
erase/reprogram the whole system if a single node failed (and could not be
removed from the network - there were a lot of early device failures).
Whether these were just growing pains that have since been solved, I can't
say. You might want to review the threads here where the author of
CharmedQuark discussed some of these issues. With multiple vendors it may be
that some have addressed the issues while others have not.

BTW, I found a reliable source for the 64KB EEPROM and am again actively (if
slowly) working on roZetta. I've decided to switch to PureBasic for the PC
side so I can supply interfaces for Windows and Linux (and Mac when there's
an Intel Mac release of PB). I'm gradually grasping PB and hope to be trying
to figure out how to enumerate the COM ports (USB->serial included) with PB
under Linux sometime next week. Tibbo has virtual serial port drivers for
Linux so I need to learn how to detect those as well.