[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

Re: Wireless system thoughts, please read and reply



An answer to your question is to look at automotive computers and how
they work internally. Or to look at the "programming" for a computer
in a car.

You will not find this information! Period!

Why? Because it costs companies tons of money to develop this stuff
and they don't want their competitors to copy their designs.

That is the nature of the electronics industry.

Then many technicians in the field - automotive, electronics,
appliances, whatever... are not software engineers. For repair,
knowing just how to replace an entire faulty circuit board takes a LOT
less training than hiring tons of people who are "software engineers"
or "electrical engineers". Plus you can't find enough of these people
even if you could pay them and did try to find them.

Anyway there is no need for field technicians to know more about an
electronic product other than to determine if a circuit board or
component is working or not. Then if not working, they replace the
circuit board / part.

Now add to this the field of security. The idea is to not advertise
how these things work. Also to make them work differently from model
to model. And to make them work "randomly" and not in any predictable
way.

So *nothing* is going to be "the same" in the field of security. You
will find that some manufacturers intentionally design things
differently.

So for every product which works one way, you will find many others
which work differently.

Same with wire colors used. In some cases all the wires are the same
color. This is intentional so no one knows what wire is what.

And you certainly are NOT going to find a "security system wire color
code standard" anywhere!

And that is the idea. No idea what is installed where or how exactly
it works.

FYI - Look at another field. Home heating systems or home central
vacuum systems and the wire colors they use. What color wire is for
what? No telling is the answer! Whatever colors the technician or
do-it-yourself installer decided to use. And that has no need for
security, just the way things are.

Now add to all that the personality and culture of security people.
For some situations you sign all sorts of "non-disclosure" agreements
which say you are NOT to discuss anything to do with this and that.

And you may not be sure exactly what you can or can't discuss, so
safer to not discuss anything!

Also look at law enforcement people. It is common for a Sherriff's
department to not share information with a city Police department
which would help solve a case...

In the security field, it is like pulling teeth to get anyone to share
information about anything even when you are authorized to know all
about something!

If you are interested in electronics, you will have better luck
learning/experimenting with non-security related wireless devices
here...
http://www.crazyengineers.com/forum/forum.php



"mister accavanno"  wrote in message
>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



alt.security.alarms Main Index | alt.security.alarms Thread Index | alt.security.alarms Home | Archives Home