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Wireless system thoughts, please read and reply



I just got this job installing alarm systems. Now, listen, I am not a
certified technician, but more of a helper. So please bare with me
with these questions I have. My boss is a dick and I think is just a
miserable bastard. So I do not communicate with him at all. Plus, I
have not attended any technical or alarm installing classes.
I just am intrigued with the way this electronic equipment
works(communicates via airwaves, rf, ir, etc.). I know I am putting
myself at risk by asking such trivial questions and therefore will
probably be flamed with such responses like read a damn book, or
search on technical websites for the information. I do not have the
books, or any manuals and even the manuals I do get to read are only
related to the system we are installing at the time. It doesn't
inform
me with the information I am about to ask about. The last post I
posted, resulted with a with a few replies but did not inform me with
the technical details for which I was hoping for.
I am concerned with wireless systems and the way the sensors
communicate with the Main Control Panel. Now, if you think that the
answers are a bit top secret and should not be described on a
security
forum such as this, I understand and will find the information
elsewhere, someday. It is not a life or death situation here, with
me.
I am just intrigued. I have some interesting thoughts on this subject
and depending on the responses I receive, I will disclose my thoughts
about this wireless intruder(burglar) industry. I think some of you
will be interested with what my thoughts are. My name is not
Paul(whoever that guy is). From what I understand by now, this guy
Paul has been a pain in the ass to many of this newsgroup's members.
Okay, we have the Main Control Unit, along with the pir sensors and
all the perimeter units on the doors and windows. I know there are
many other sensor units that detect noise, vibrations, etc. As I
stated in one of my first posts, when the owner of the house, or
retail store, or whatever warehouse or building is being secured by a
wireless system, leaves the premises and activates their alarm
system,
the system is now in the armed mode. My question is, while in the
armed mode, the sensors are up on the wall probably with a green
diode
light blaring without a blink. If the information I have already, the
sensor transmits a certain code every so often as programed. This
periodic transmission is a packet of some sort telling the MCU that
it
is working properly(that is is still there, the battery is still in
good condition, all is well, etc.). Other than that, the sensor is
just there in an idle mode. That is until an unidentified object
consisting of a certain amount of heat passes through it's protected
area. At that point, if I am correct, the unit transmits a message
that tells the MCU that the closed alarm loop has been broken at that
zone. An alarm message is then sent to the central monitoring
station.
Am I correct at this point? Please comment as to what I have written
so far.
Okay, if while the system is armed and the owners of the facility are
away, the sensor is idle and only transmits to the MCU the "all is
well" packet periodically as programmed. Now, without any detection
of
an intruder passing by, how often does the unit transmit these
packets. There is probably an industry set amount of minutes or hours
that these are sent, right? At that moment is there a blink in the
green diode on the unit, or no? I am aware that most of the
frequencies used in the USA operate on either 315mhz, 433mhz, or
868mhz, am I correct? When these packets are sent to the MCU what do
they consist of? Is it just a burst of one of these frequencies, or
are they encoded or encrypted with a particular message? Once again,
exactly how many minutes apart are they sent. Don't get me wrong, I
think if I just sit under the sensor in a blind spot with a rf
frequency counter, I would be able to determine exactly when they are
transmitted. We are talking only about wireless systems here. I do
have an underlying interest for asking these questions and when an
expert in this forum addresses my post, I will initiate a very
interesting discussion. Please give me a full explaination to all
parts of my post. Trust me when I say that you will be interestingly
surprised to what my thoughts are regarding this subject matter.
Thank you,
Frank Accavanno


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