NAL Research Corporation (451-93156-002A)
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NAL Research offers several types of antennas for use with the A3LA-RM modem. These antennas
include the fixed mast, mobile magnetic/permanent mount and portable auxiliary. For low-cost and
applications where small form-factor and light-weight are required, NAL Research recommends model
SYN7391-C. If the specific application requires a custom antenna, it must meet the specifications below.
Satellite signal strength reported by the A3LA-RM when issuing an AT+CSQ command indicates the
signal strength of the ring channel. Care should be taken when using this signal reading for comparisons
between devices. Of particular notes are the followings:
1.
There is a 0.5 dB tolerance on the calibration.
2.
Each bar represents a 2 dB increment.
3.
Multiple ring channels can be present at the same time so units can lock to different signals.
4.
If the reading is near the decision threshold it would be easy to see a 1 bar difference.
5.0 SIM CARD INTERFACE
The A3LA-RM modem contains an integrated SIM reader. The modem uses and requires an Iridium SIM
chip for operation. The SIM chip is inserted into the opening located on top of the modem as shown in Figure
4. A plastic locking mechanism is used hold the SIM in-place. Place the SIM chip (facing down) into the SIM
reader’s bracket. Make sure that the cut-off on the SIM chip aligns with the SIM reader.
6.0 LED DISPLAY
The A3LA-RM has three status LEDs depicted as P for power indicator, I for Iridium satellite signal
strength and S for status (see Figure 5). They offer users a quick visual check to ensure proper modem
PARAMETER
VALUE
Operating Temperature Range
–40
o
C/+85
o
C without loss of function
Measurement Frequency Range
1616 to 1626.5 MHz
VSWR
< 1.5 : 1
Maximum Gain
3 dBic
Nominal Impedance
50 Ohms
Polarization
Right Hand Circular (RHCP)
Basic Pattern
Omni directional and hemispherical
SIM Reader
Figure 4. Location of the SIM Reader.
