NAL A3LA-XM, Общее описание устройства

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NAL Research Corporation (TN2009-25-V1.0)
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level (i.e. low) for at least 270 ms and released, the A3LA-XM will alternate from its current on/off state. The
current drawn on the external load used to pull the A3LA-XM to GND is no more than 0.5mA. The signal on
pin 1 is considered GND when it is at 0.5V or less.
Cables used to supply power to the A3LA-XM should be kept as short as possible to prevent significant
voltage drop, which can cause the A3LA-XM to malfunction during a data call, a voice call, an SMS session or
an SBD session. Power reset by the A3LA-XM during a call is an indicative of the DC power source unable to
sustain voltage above 4.0VDC at peak current demand.
3.5 Audio Interface
The A3LA-XM supports both digital and analog audio I/O. The digital audio is in PCM format. In such
format, digital audio cannot travel far (less than one foot); this is why the analog is chosen for the A3LA-XM
audio handset. The analog audio input is a single-ended, unbalanced input with a minimum impedance of
10k to ground. The A3LA-XM accepts a maximum input level of 2.0V peak-to-peak without signal
distortion. The analog audio output is also a single-ended, unbalanced output capable of driving an
impedance of 600 or more to ground. The A3LA-XM delivers undistorted audio up to 2.0V peak-to-peak at
this port.
The combined analog I/O audio interface (pins 5 and 15) and the DPL UART I/O interface (pins 18 and
20) enable an analog audio handset to be connected to the A3LA-XM. The signal level for the DPL I/O can be
RS232 or logic level. The level can be selected using a switch that is accessible when the SIM cover plate is
removed. With the DPL audio handset model DPLS0401-X and DB25 data kit model HRC-24-8X/XU, the
A3LA-XM can be used both as data modem and a satellite phone (see Figure 4). This setup can be an
extremely useful developmental tool since the modem status can be seen on the handset LCD similar to a
9555 Iridium phone.
3.6 Digital Peripheral Link (DPL)
The DPL interface is composed of two ports—a full duplex asynchronous serial link for control messages
and a PCM digital audio link for audio traffic. The protocol used on these ports is made available to
application developers only on a case-by-case basis and after appropriate Non-disclosure Agreements and/or
License Agreements are executed.
Figure 4. A3LA-XM connected to a DPL handset, AC adapter and data Kit.
DPL Handset
Model DPLS0401-X
AC Adapter
Model LA-3098
DB25 Data Kit
Model HRC-24-8X