Re: another newbie, what to do with this Brinks alarm system?

[G. Morgan <alarmpro@xxxxxxxxxxx>]

On 03 Nov 2006 16:08:46 -0600, t@xxxxxxxxx (Todd H.) wrote:

>"Crash Gordon" <webmaster@xxxxxxxxxxxxxxxxxxxxx> writes:
>
>> Basically you throw out the alarm panel and the keypads and buy something
>> else you can install your self. Everything else should be reusable although
>> you might have to look for buried resistors if they put them at the end of
>> the line and remove them.
>
>Cool--this is sort of what I envisioned.   I did see in the alarm
>panel a small pack of resistors just kinda sitting there hanging -- as
>though it was something they used as piece parts for whatever reason.
>
>When you say end of the line, you mean on the sensor end of the line?
>And at the risk of asking what may be a FAQ, what purpose do these
>resistors serve to the Brinks system?  (I'm new to the security system
>hacking realm, but have a strong background in electronics, for
>whatever that's worth).
>


EOLR's are used to supervise the alarm loop.  With a preset resistance
on the loop the panel is monitoring the current in the circuit, now it
can detect open, close, and partial short -- as well as tampering with
the circuit between the control and device.

Most residential installers disable EOL supervision in programming and
just go for a open/close, that or put the EOLR in the panel which
completely negates the whole purpose of the EOLR in the first place.


Think about knocking out a brick under a window and putting hemostats
on the wire, BEFORE it reaches the contact and you'll see why EOLR's
are useful.

--

-Graham
(remove the double e's to email)