User's Manual

Electrical Description
3. Electrical Description
The siren unit (see Figure 3) is basically composed of a Main board
which receives a number of external triggers, and generates
audible and visual indications according to a pre-programmed
microprocessor.
BACK - UP
BATTERY
TRANSCEIVER
PCB
MAIN
BOARD
16 VDC INPUT
TAMPER
SWITCH
STROBE
BOARD
FIRE ALARM
Wired version only *
Speaker connector
Ground
* FIRE & ALARM are
relay contacts in the host
panel or switches used
for testing.
Figure 3: Siren Unit Block Diagram
3.1 Alarm Operation
The microprocessor is activated by fire or alarm inputs, and
accordingly generates one of two sound patterns and related
flashing strobe indications:
• Burglar (or panic) alarm sound – the strobe flashes until
the input is restored to normal condition. The speaker in
the siren outputs a loud 1300 to 1800 Hz continuous
sweeping sound, having a 100% duty cycle. The alarm
sounds until the timer runs out (5 or 15 minutes). The
strobe continues to flash, even when the sound has
ceased, until the unit is reset.
• Fire alarm sound – the operation is similar to that of the
burglar alarm, with the exception of the audio sound
from the speaker. The siren sounds off at 800 to 850 Hz,
Page 6 SA-80A Installation Manual