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

["Mark Leuck" <m..leuck@xxxxxxxxx>]

"Robert L Bass" <RobertLBass@xxxxxxxxxxx> wrote in message
news:NMqSi.884$uE4.355@xxxxxxxxxxx
> "Michael" wrote:
> >
> > 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...
>
> There's a reason for that.  If you're using a multi-format receiver,
> it sends each possible handshake tone, waits a second or two, tries
> again (or not) and then sends the next one, repeating until the
> communicator hears a tone it likes and begins transmitting.  I used a
> number of different receivers over the years.  The last ones were O/H
> QuickAlert II.  Because we used almost exclusively Ademco CID once it
> became available, I had O/H make us a set of custom chips.  Our
> receivers would first try Contact ID, then pulse, etc.  This shaved a
> few seconds off the connect time for newer systems.

Ancient technology, SurGard's MLR-2000 and System III remember the last
working format then gives it as the first handshake the next time the panel
calls

"custom chips"? LOL!

>
> BTW, I said "receivers" as in two of them.  We were small.  We only
> needed one 4-line receiver and another for backup.

How cheap, a backup receiver but no backup central station tsk tsk