Protect Alarm System
The alarm unit is equipped with an accelerometer, allowing movement detection without using an external tilt switch (TILT1 jumper must be shorted). If no power is applied, the alarm unit will run on the on board battery. The battery can be disabled with the BATTERY1 jumper. When an alarm is active, the attached siren will be powered with 9Vdc, giving a loud signal. The optional relay on the board can be used to attach other alarming devices. The alarm sound is turned off automatically after approximately 2 min, and the armed state is entered again. During arming, when the key switch is opened, the attached led indicator flash approx. twice per second. When the armed state is entered, the led indicator remains on, indicating that the unit is armed. When the alarm system is armed without external power supply, the indicator led will remain flashing approx. twice per second to save energy. When the alarm unit is disarmed, by closing the key switch, the attached led indicator will be switched off, and the door and tilt switches and accelerometer are disabled. Note that after the unit goes into the armed state (led indicator on), the tilt and movement sensor are monitored 2 min later, to allow some epositioning of the machine. After this 2 min delay, the siren will beep twice shortly to indicate that the tilt inputs are active now. The unit can be installed in different ways, depending on the application. Two applications will be explained below.
The minimal installation uses no door switch, no tilt switch and no key switch. The door switch input is shorted to GND via a link at the connector. The tilt and key switch input are left open.
Jumper AUTO1 must be shorted to enable automatic arming. As soon as the unit is powered, either by placing the battery jumper or using a power supply, the alarm unit will go into alarm state 10 sec later. The tilt and movement sensor are monitored 2 min later, to allow some repositioning of the machine. If the alarm unit is moved, the on board tilt detector will generate an alarm. The alarm is reset by pressing the key switch button on the board momentarily. As soon as the switch button is released, the unit will go into alarm again 10 sec later. When the unit goes into alarm state, the current position of the movement detector is stored. Any new movements will generate an alarm again. Typical applications using minimal installation include movement detection like opening doors, windows, etc. The alarm unit is mounted on the door itself.
If no automatic arming is used (AUTO1 jumper open), the key switch is used to arm (switch open) or disarm (switch closed) the alarm unit. A door switch is used to detect door opening and closing. A tilt switch may be connected to detect movements. As soon as the key switch is opened, the arming timer starts and 10 sec later the unit is armed. If the door is still open, an alarm will sound. Close the key switch to disarm the unit, and silence the siren. The tilt and movement sensor are monitored 2 min later, to allow some repositioning of the machine. Some applications have no alarm key switch or have their alarm key switch located behind the door.
In these cases, open the door, arm the unit by opening the key switch or pressing the small push button. If no automatic arming is used, close the door within 10 sec, and the alarm unit is armed 10 sec after the door was closed. If automatic arming is used (jumper AUTO1 shorted), the unit will start arming when the door becomes closed. If the door is opened, the alarm will not go off immediately, but after a door entry delay of 8 sec (3 if the DELAY1 jumper is shorted). During this delay, the user may disarm the unit by closing the key, preventing a door alarm ccurring. If the door is closed without closing the key switch, the alarm unit is not armed. To warn the user in this situation, jumper SOUND1 may be shorted. Then the sounder will beep twice per second in this situation. Applications include slot machine security, changing machines, etc.
If the AUTO1 jumper is shorted, the alarm unit will go into arming state as soon as the door is closed. This installation is used, when no external key switch for arming and disarming is desired. Once the door is closed and the unit is armed, then if the door is opened, the alarm unit may be disarmed within the door open entry time, by pressing the ARM/DISARM1 pushbutton on the PCB. During the 10 sec arming time, the indicator led flashes.