NAL Research Corporation (TN2004-39-V3.2)
3
4.
Connect a DTE (data terminal equipment such as a computer, a data logger, a microcontroller, etc.)
to the modem DB25 port using the HRC-24-7 cable provided. The HRC-24-7 cable consists of a full
DB-9 serial connector and two terminal leads for power input. Three-wire (TX, RX and GND) serial
cable can also be used (see document TN2002-38-V2.2) if flow control is not required. The A3LA-I
will automatically adjust to the DTE baud rate.
5.
Connect an external antenna to the Iridium modem. Any of the four types of antennas offered by
NAL Research is appropriate. Make sure the antenna has full view of the sky and the cable loss
between the modem and antenna is less than 3 dB.
6.
Supply DC power of ~4.4V (can range from 4.0VDC to 5.0VDC) to the two power input wires of the
HRC-24-7 cable. Highest current drawn will be at power-up and approximately [email protected] for
less than 500 milliseconds. The modem will automatically be ON/OFF when DC power is
applied/removed. If power to the modem is cycled, make sure the elapsed time between each
power cycle is approximately 10 seconds. NAL Research’s AC adapter model LA-2098 (purchase
separately) can be used to power the A3LA-I (see picture below).
4.4 V
DC
RS2
32
NA
L R
esea
rch
Antenna
HRC-24-7 Cable
AC Power Adaptor
Model LA-2098
Iridium Antenna
Connector