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ICP-CC408 | Installation Guide | 22.0
22.0 Appendices
22.1
Appendix A – Telephone Anti-
Jamming
Many companies import American-designed
products claiming to have anti-jamming, and push
this feature as if it were a major breakthrough in
control panel technology. This is not the case
because most control panels have an anti-jamming
feature. In the early 1980s, even the 678 Dialers
incorporated a form of anti-jamming as a standard
programmable option.
It is important to note that most American-designed
products are primarily aimed at their local market and
telephone networks. When these products are
imported to Australia, their anti-jamming functions do
not perform as they should.
To define anti-jamming and explain how it works
requires an understanding of telephone networks. In
America, either of the two parties (that is, the one
who initiated the call or the one receiving the call)
can clear the line by returning the hand piece to the
hook. If you pick up the hand piece again, a dial tone
is received and you can make a new call
immediately. That is not so in Australia.
In Australia, only the calling party can terminate the
call immediately. If you receive a call from someone
and hang up, picking up the hand piece again to
make a new call only reconnects you to the original
caller. It is impossible to make another call until the
original caller hangs up or you hang up the phone for
90 sec or longer. Australia is different and needs a
special form of anti-jamming for its telephone
network.
There are control panels on the market that, after
making a few unsuccessful call attempts, simply hang
up and wait for 90 sec to clear the jamming incoming
call. This may work in some instances where the caller
is not a burglar and is not deliberately trying to jam
the control panel. With this simple method of hanging
up for 90 sec, not only is the alarm signal delayed for
this time, but also the time taken for the original failed
call attempts (these could easily total 4 min). This is
bad enough, but even more disturbing is that the
initial failed call attempts allow for the establishment
of an audio connection between the would-be burglar
and the control panel. Anyone with some knowledge
of alarm systems can trick the dialer that it is
communicating to a base station and clear the alarm
signal. It is frightening when the control panel you use
and recommend to your customers is supposed to
have anti-jamming.
Bosch Security Systems, Inc. | 12/08 | F01U089463-02
Appendices
Bosch Security Systems, Inc. takes anti-jamming
seriously and devotes much time and money
researching this problem. Our engineers designed the
best possible anti-jamming procedure known and
patented it accordingly (Patent Number 571994).
Our procedure is very simple and effective because
we never answer the burglar's phone call and the
Telecom Network automatically clears an
unanswered call in approximately 90 sec. This time is
shorter if the call is originated through the Mobile-
Net Network where it will most likely be in the case
of a true burglary.
When the control panel detects that the phone line
has stopped ringing, it immediately loops the line
and makes its call, thereby transmitting its alarm
message successfully. The line is also automatically
disconnected from the telephones within the
protected premises immediately on an alarm
condition by the control panel to further confuse the
burglar and eliminate the possibility of the burglar
answering the call. In the worst case, our method of
anti-jamming delays the alarm signal by 90 sec, but
even more important, never allows an audio
connection between the burglar and the control
panel.
All dialing products produced by Bosch Security
Systems, Inc. since 1985 incorporate this true anti-
jamming feature as standard. We do not consider it
an option but a must in any professional security
system.
Only Bosch Security Systems, Inc. products have true
anti-jamming. Other manufacturers can offer only
second best because of our patent for this very
unique and effective procedure.
22.2
Appendix B – Test Reports Only
When Armed
The ICP-CC408 Control Panel allows Test Reports
to be sent to the base station receiver to verify that
the dialer is functional. Most alarm dialers allow you
to do this.
The one problem is that installations that send
Opening and Closing Reports generally also send a
Test Report each day. This call is unnecessary
because a successful Opening and Closing Report
means that the dialer is functioning correctly.
The ICP-CC408 Control Panel allows you to save
time and money by providing Test Reports only
when the system is armed.
EN | 96
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