Re: SIA, Contact ID, 4/2, 3/1

[Michael <sirflannelS@xxxxxxxxxxxx>]

One thing I have thought about it is, that using the latest higher
speed transmission format has it's own problem. How long does it take
two modern modems to negotiate a connection? 5-10 seconds? It seems
(from what I've noticed over the years), that the faster the overall
transmission speed, the longer it takes to actually negotiate the
connection and sync the signals. To transmit the CID, that two tone
signal takes about a half second? By the time the latest protocol has
been extablished, the older formats have finished sending their
signal. There's not a tremendous amount of data needing to be sent (a
few bits at most), so having to negotiate a high speed connection
seems to me to be a waste of time. Of course, that's just MY opinion,
I could be wrong

On Fri, 19 Oct 2007 12:45:03 -0500, "Just Looking" <nospam@xxxxxxxxxx>
wrote:

>For the most part modems are built into panels these days. There are add on
>dialers for fire panels, as well as old slave dialers here and there. Modem
>speeds in alarm panels are a function of the price of the panel itself.
>Unless or until folks are willing to pay more, or the cost of the chips
>themselves change, it's likely to stay the way it is.
>
>"JohnO" <johno@@&%heathkit##.com> wrote in message
>news:eI3Si.15374$JD.13275@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>> > I'll let Mark Leuck answer about SIA, but I can tell you about 4X2 3X2
>> > and CID.
>>
>> (I've been out of town a few days...) I appreciate the SIA code list, but
>> that doesn't give me much in the way of the SIA Big Picture. Help me out,
>> Mark...
>>
>> After a bit of googling, I found some posts from 2002 that say SIA is a
>> modem-based approach, where SIA has defined the signaling protocols and
>> alarm codes.
>>
>> Questions: Is SIA widely used? Why or why not? Still 110 and 300
>baud? ---Is
>> the idea that 110/300 is plenty fast enough for a pile of codes, and more
>> reliable than V.42bis and all that new fast stuff? These modems, are they
>> typically standard external boxes with serial cables, or built into the
>> panel or mainboard?
>>
>> Thanks!
>>
>> -John O
>>
>>
>>
>