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ICP-CC488 | Installation Guide | 23.0
23.0 Appendices
23.1
Appendix A – Telephone Anti-
Jamming
There are many companies that import American-
designed products claiming to have anti-jamming,
and they push this feature as if it were a major
breakthrough in control panel technology. This is not
the case because most control panels have some sort
of anti-jamming feature. We can go back to the early
1980s where even the 678 Dialers incorporated a
form of anti-jamming as a standard programmable
option.
The important thing to note is 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 clear up what anti-jamming is and how it works
needs some 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 placing the hand piece back on
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 here in Australia.
In Australia, only the calling party can terminate the
call immediately. If you receive a call from someone
and hang up, picking the hand piece back up 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 ninety sec or longer. Australia is different
and needs a special form of anti-jamming its our
telephone network.
There are control panels on the market that, after
making a few unsuccessful call attempts, simply hang
up and wait for ninety sec in an attempt 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 ninety 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 a little knowledge of alarm systems can
trick the dialer that it is communicating to a base
station and clear the alarm signal. It is pretty
frightening when the control panel you use and
recommend to your customers is supposed to have
anti-jamming.
Bosch Security Systems, Inc. | 12/08 | F01U089457-02
Appendices
At Bosch Security Systems, Inc., we take anti-
jamming very seriously and have devoted a great
deal of time and money researching this problem.
Our engineers have 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 possible case, our
method of anti-jamming delays the alarm signal by
ninety sec, but even more importantly 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.
23.2
Appendix B – Test Reports Only
When Armed
The ICP-CC488 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-CC488 Control Panel allows you to save
time and money by providing Test Reports only
when the system is armed.
EN | 99
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