From: brian@navaho.eel.ufl.edu (Brian Gentry)
Subject: Re: Car Alarms
Organization: UF EE Department (student)
Date: Fri, 8 Jan 93 19:07:53 GMT

In article <1993Jan8.060658.10312@lds.loral.com>, kurnik@lds.loral.com (Timothy J. Kurnik) writes:

[...]
|> Anyway, if it turns out that the alarm needs replacing, I'd probably get the same
|> one.  Although I haven't looked into it very deeply, I've heard the Viper alarm is
|> pretty good.  Any comments?

I've had a Viper 600 for about 2.5 years now.  It recently developed an
intermitent problem, so I called Directed Electronics (they make Viper)
and they said to go to the dealer and get it replaced since it has 
a LifeTime waranty.  Well I got a new one and installed it.  It has a
lot of features that my old one didn't.  Here's a quick rundown:

1.  All of the standard features you'd expect (door pins,
passive or active arming, flashing lights, etc).

2.  Six tone "revenger" siren.  Any of the tones can be omitted to
"customize" the sound of your alarm.

3.  "Dual stage" shock sensor.  This is a feature I REALLY like and
I wish I'd thought of.  When the shock sensor is activated by a short
or low intensity shock, it chirps the siren.  A longer or higher intensity
shock causes the alarm to activate.  This is cool because you can set
your sensitivity pretty high and the worst false alarm you'll get is
one chirp.  This is good for loud trucks, thunder, a cat jumping on your 
hood, etc.  This required one external relay to do the "chirp".  If I
had the optional battery back-up siren, I wouldn't have needed the
relay.

4.  Diagnostics.  One chirp for armed, Two chirps for Disarmed.  
Three chirps indicates that the alarm was armed AND one of the zones was
active while it was armed.  This zone was bipassed.  For 30 seconds after
the Three chirps, the status LED blinks in groups of one, two, or three
to tell you which zone was active.  Four chirps indicates a disarm and
that the alarm was activated while you were away.  After the Four chirps
the LED does the same behavior as above to tell you which zone was activated.

5.  Transmitter coding.  My old Viper 600 had 1024 codes.  My new one has
2^29 ~= 533 million codes!

6.  Chirp disable.  You can permenantly disable the chirps with a switch on
the "brain" OR you can disable the chirps once by pressing button 2 for
one second and THEN button 1.  This is usefull for not disturbing your 
neighbors.  BTW, the Four chirps that indicate a violation can NOT be
defeated with either of these methods.

7.  Power door locks.  There are relays on board to control factory or
after marker power door locks.  My old Viper had this.  The new feature
is that the locks are also tied to the ignition key.  When you turn the
key to the "on" or "running" position, it locks the door locks.  When you
turn the key to "off" the alarm unlocks the locks.  This is a nice safety
feature.  This feature is defeatable at the brain.

8.  Starter kill.  Relay is on board the brain.  Defaults to startable.
If the alarm brain gets fried, the starter kill doesn't work.  I like this
because it won't leave me stranded if my alarm fails.

9.  Domelite supervision.  Requires one external relay.  Turns on your
domelight for 30 seconds after you disarm the alarm.  Another nice safety
feature.

All in all, I'm really satisfied with this alarm.  In addition, Directed's
technical support team has been very nice and helpfull with obscure
problems (like my intermittent problem I mentioned above).

			Brian L. Gentry
		   (brian@sioux.eel.ufl.edu)