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15-1
INTRODUCTION
This manual contains information for using the
R2670 FDMA Digital Communications System
Analyzer with ASTRO Options. The ASTRO
Option
provides unique testing features for
communications equipment using ASTRO
encoding and modulation principles. Standard
R2670 capabilities are retained. The additional
ASTRO test sequences are accessed via the
LCD display, screen-defined softkeys, numeric
keypad, cursor movement keys, and optical
tuning knob. The ASTRO Option functions
may also be accessed via the remote control
interface port.
15-2
CAPABILITIES
The ASTRO Option gives the R2670 the
capability
of
monitoring
ASTRO signals. An ASTRO signal relates to a
Motorola proprietary signaling scheme in
which a 12 kbps serial bit stream is mapped
into one of two corresponding amplitudes,
filtered digitally, and then modulated onto an
RF carrier. Most of the ASTRO user interface
operates exactly like that of the standard
R2670. Several new features were added to
test the unique requirements of user ASTRO
equipment.
Voice Mode System Testing
Voice mode provides ASTRO-compatible
modulation and demodulation with vocoding.
The ASTRO Option generate and monitor
modes support actual functional voice testing
in encrypted mode using either a test key or
an operating key loaded from a separate
compatible keyloader.
Section 15
ASTRO OPTION INTRODUCTION
and
generating
207
Bit Error Rate (BER) Testing
A BER test pattern can be selected to
modulate the R2670 generator section.
BER test pattern, likewise, can be decoded
by the R2670 in monitor mode. BER tests
can also be conducted in duplex mode for
loop testing.
Dedicated Test Screens
Dedicated test screens can be setup as a start-
up default condition or as a programmable
test set-up. Dedicated ASTRO test screens
are zoned with RF and Audio Modulation
control screens to simultaneously display test
results along with their test conditions.
Baseband Audio Scope Display
The display provides a graphic image of the
audio baseband signal. This baseband signal
is selectable at either the vocoder input in
generate mode or the vocoder output in
monitor mode.
15-3
ASTRO OPTION HOUSING
15-3.1 Description
The ASTRO Option housing (figure 15-1) is an
external module containing circuitry and
connectors to support ASTRO functions. The
ASTRO Option housing attaches to the rear of
the R2670 analyzer. In some instances the
Option housing may be attached along with
another option housing or in conjunction with
the R2670 battery pack (optional). The battery
pack, if used, mounts on the back of the final
option housing.
A
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