GENERAL DESCRIPTION
GENERAL DESCRIPTION
The GEM-DT is an advanced dual-technology sensor designed for use
with Napco’s GEM-Series wireless receivers. The unit is powered by four
1
1
⁄
2
-volt C-size alkaline batteries (supplied). Battery life expectancy is 4
to 5
1
⁄
2
years, depending upon the amount of activity in the protected
area. When battery voltage drops below normal, a low-battery report will
be sent to the receiver. Note: To conserve battery life, alarms are sent
no more often than once every 5 minutes.
Coding switches are not used in the GEM-DT. Each transmitter has a
unique factory-programmed RF ID code (printed on the unit) that distin-
guishes itself to the receiver. (Note:
Note: See control-panel instructions for
entering this six-digit hexadecimal code and checksum digit into the
panel; be sure to enter all numbers and/or letters, including leading
zeros, if any.)
SPECIFICATIONS
SPECIFICATIONS
Coverage (l x w):
Coverage (l x w): 40’ x 40’ (12.2m x 12.2m) at 20°C (68°F), typical.
Operating Temperature:
Operating Temperature: 0° to + 50°C (32° to 122°F)
Self-Test Interval:
Self-Test Interval: 11--16 hours
Microwave Frequency: 10.525GHz
±
25MHz
Recommended Mounting Height:
Recommended Mounting Height: 6--8’, wall or corner
Dimensions:
Dimensions: 5.5’’ x 3.25’’ x 2.4’’ (14cm x 8.3cm x 6.1cm) (HxWxD)
Shipping Weight:
Shipping Weight: 1.2 lb (600 gm)
LENS
LENS
FEATURES
FEATURES
•
Signal Selective Processing for reliable operation
•
Power-up system diagnostic tests virtually all electronics
•
Microwave and PIR self test
•
Watchdog microprocessor supervision
•
Unique circuit design protects against false alarms due to radio-fre-
quency interference
•
Dual-element PIR sensor
•
Automatic PIR operation on microwave failure
•
High-efficiency, dirt-resistant grooves-in lens with ‘‘look-down’’
beams; large area assures high sensitivity
•
Bracket-free wall or corner mountable; universal swivel-bracket (SVL-
BKT) available
•
Vertical and horizontal aiming capabilities
•
Built-in tamper microswitch
MOUNTING
MOUNTING
Open the case
Open the case
To open the case, insert a screwdriver into the slot at the bottom and
push up slightly while pulling the front cover out at the bottom. (To
replace the front cover, engage two retainer tabs at the top into the slots
in the case and push in at the bottom until it snaps into place.)
Mount the unit
Mount the unit
Remove the front cover as described above and proceed as follows.
1. Loosen the Height Scale Lock Screw fully. (This is a captive screw
and won’t fall out.)
2. Remove the circuit board: apply pressure against the left side of the
cavity and lift out. See Fig. 2.
3. Remove the battery holder by removing the two screws ‘‘A’’ shown
in Fig. 3.
4. An assortment of ‘‘push-thru’’ holes is provided in the rear case for
wall or corner mounting. Open desired holes and use case to mark drill
holes.
5. Select a location where intruders will pass across the field of view.
Also consider the size and shape of the area, objects that may block
detection, and animals within the protected area.
6. Mount unit using screws suitable for the surface material. Note:
Note: (1)
Use the caulking material supplied to seal any unused mounting holes.
(2) If mounting higher than 10’, it may be necessary to tilt the unit
downward slightly for proper microwave coverage, and to reset the
Height Scale for proper PIR coverage.
Install the batteries
Install the batteries
1. Replace the battery holder using
the screws removed in Step 3 above.
2. Install the four C batteries (sup-
plied) over the pull ribbons, observing
polarity shown in Fig. 3. (LED will start
to flash. See Power-Up Procedure.)
3. Replace circuit board: slip the right
side under the retaining tab in the case
and push down on left side to snap the
board into place.
4. Replace the Height Scale Lock
Screw and set at mounted height of unit.
POWER-UP PROCEDURE
POWER-UP PROCEDURE
LED Indications
LED Indications
When power is applied, the LED will display the following sequence
of indications.
Rapid flash. For the first 5 seconds after power-up, the LED will flash
rapidly to indicate that the unit has been energized.
Slow flash. After 5 seconds, the LED will start flashing slowly to
indicate a 1-minute warmup, during which a self test is performed.
LED off. After the warmup/self-test interval, the LED will go off.
Approximately 15 seconds thereafter, the unit is ready for operation.
Self Test
Self Test
The self-test diagnostic simulates motion and tests the PIR amplifier
and related PIR circuitry, and the microwave circuitry. This test is initiated
each time the unit is powered up and at 12-hour intervals after the last
alarm to assure that the unit is always in operating order. At power-up,
the LED will flash. If the unit is operating properly, the LED will extinguish
after about 1
1
⁄
2
minutes. If it fails the self test, a Self-Test Failure system
trouble will be sent.
ADJUSTING THE COVERAGE AREA
ADJUSTING THE COVERAGE AREA
Setting the Height Scale
Setting the Height Scale
The Height Scale must be set to obtain the maximum recommended
coverage. Remove the front cover; the Height Scale is printed along the
edge of the circuit board at the lower-right corner of the shield (see Fig.
2). Scale calibrations represent sensor mounting height. To set, loosen
the Lock Screw and slide the board up or down, and align the the index
in the case with the calibration representing the mounting height of the
unit. Then tighten the Lock Screw (do not overtighten!).
Reducing Insensitive Areas
Reducing Insensitive Areas
The insensitive area is the area just beneath the sensor wherein an
intruder may not be detected by the PIR beams. This area is a function
of mounting height and Height-Scale setting. When used in a room or
area that requires less range than the recommended maximum, the
Fig. 1. Coverage pattern for 6’ mounting height.
Fig. 1. Coverage pattern for 6’ mounting height.
Fig. 2. GEM-DT, front cover removed.
Fig. 2. GEM-DT, front cover removed.
GEM-DT
GEM-DT
Wireless PIR/Microwave
Wireless PIR/Microwave
Transmitter
Transmitter
© NAPCO 1996
WI806 10/96
Fig. 3.Battery polarity.
Fig. 3.Battery polarity.
