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INSTALLATION AND OPERATION INSTRUCTIONS — PERSONAL ALARM SYSTEM
2.0 THEORY OF OPERATION
2.1 System Concept
2.1.1 The PAS-120 System was developed from the concept that an ultrasonic signal
will not penetrate the walls, ceilings or barriers, so a reliable indication of the location
is provided. At the same time, the ultrasonic signal will bounce off most surfaces,
providing signal coverage even though the path to the receiver may not be clear.
The transmission of ultrasonic signals works particularly well in facilities with pre-
dominately hard surfaces such as correctional facilities, courtrooms, hospitals, and
schools—all prime users of modern personal security systems.
2.1.2 Ultrasonic personal alarm systems developed in previous years unfortunately
have been plagued with a high number of nuisance alarms.These nuisance alarms
usually occur because another piece of equipment makes a signal that is similar to the
ultrasonic signal used by the alarm system. Unfortunately, many pieces of equipment
generate ultrasonic signals.We don’t normally recognize this because the human ear is
not equipped to hear these high frequency sound signals.
2.1.3 Senstar employs a unique method of using two ultrasonic
frequencies in a preset modulation pattern to overcome these nuisance alarm
problems.With this concept, a signal must not only consist of the two frequencies but
must also be coded in the proper pattern.The combination of these new conditions
makes a nuisance alarm far less likely than with any similar personal alarm system.
2.1.4 Senstar has successfully combined this new technology with the
already proven multiplex communications alarm reporting system used for years in all
Senstar’outdoor security systems.This combination provides a superior
personal alarm system.
2.2 Transmitter (PAT/S or PAT/C)
2.2.1 Roving personnel carry a lightweight battery-operated personal alarm
transmitter.The role of the small transmitter is to quickly summon help when
necessary.This means that the location of the individual is important.
2.2.2 The portable transmitter contains a large alarm button that must be pressed to
activate the transmitter. The button is large for easy access but recessed to eliminate
inadvertent activation.The PAT/C can also be activated by pulling the built-in switch
stem (pull pin activation is optional for the PAT/S).
2.2.3 When pressed, the alarm button latches to continuously transmit the alarm
signal.The alarm transmission continues until the button is pressed again to reset.
