AOR ARD-2 User’s Manual

®

ARD-2

ACARS / NAVTEX DECODER & DISPLAY UNIT

Specification

Model ....................................... ARD-2 ACARS/NAVTEX decoder

Power Supply .................. 12V dc or 4 x AA battery cell

Current Consumption ...... Max. 280mA

Fuse ................................ 1A instantaneous

Decode Signal

ACARS ........................... Modulation MSK

NAVTEX ......................... CCIR Rec476-2B

Display ..................................... LCD 16 character x 2 line

Control ............................ LED 4 x Mode Selection (green)

Key ................................. 4 x Mode Selection

Audio signal

Input ............................... 3.5 mm mono jack

Serial Interface ....................... Connector: D-Sub 9-P male

Operating temp ....................... 0 - 45° C

Dimensions ............................. 158L x 109W x 53H mm excl

Weight ...................................... 330g excl. batteries

Carrier 2400 Hz
Bit rate 2400 bps
Code type NRZi
Length of 1 character 7 bit+1 parity

Mark 1615 Hz
Space 1785 Hz
Shift 170 Hz
Bit rate 100 bps
Length of 1 character 7 bit

1 x DECODE (red)
1 x Scroll UP

1 x Scroll DOWN
1 x Back Light ON/OFF
1 x Decode Restart

Input impedance 1k OHM
Input level 0.2 - 2V p-p
External speaker 3.5mm mono jack
Earphone socket: two, each on front
and rear panel

Baud rate: 9600 bps
Data length: 8 bit
Stop bit: 1
Parity: None
Flow control: RTS hard flow

projections

E&OE

If you think that data reception of aircraft ACARS
and marine NAVTEX is only for experienced
professional commercial operators, the ARD-2 may
cause you to think again. This decoder & display
unit has been designed with both the newcomer and
experienced "go anywhere and everywhere"
operators in mind.

The ARD-2 provides

internal batteries
the need for a computer

provides two lines of text with up to 32 characters
of text per line and a scroll back buffer of 512
characters.

Imagine sitting at an airfield with the ARD-2 in
one hand and a hand-held receiver in the other
(such as the AR8000) with just a single
connecting cable between them... its that simple.
As ACARS activity is highest during take off and
landing, you will see first-hand ‘what is
happening’... ‘who & what’ is going ‘where &
when’ !

The ARD-2 is just as capable at home offering
reception of ACARS and NAVTEX. NAVTEX
traffic (audio signal from a short wave receiver
tuned in SSB such as the AR7030) is every bit as
interesting with search & rescue, weather
warnings and other routing traffic being regularly
transmitted.

Getting started could not be easier

ARD-2 is as simple as connecting audio from a
suitable radio receiver and switching on:

1) Connect the AOR AR5000 to the AF IN of
the ARD-2 using the supplied lead.

2) Select the local ACARS VHF airband
primary frequency in AM mode: 131.550 MHz
in the USA, Canada & Pacific, 131.450 MHz in
Japan and 131.725 MHz in Europe.

3) Adjust the volume of the AR5000 to the
11 o'clock position.

4) Switch on the ARD-2 and away it goes, text

✩

‘Go-anywhere’ portable ACARS / NAVTEX decoder with built-in LCD

✩

Simple to operate

✩

Operation from 4 x AA internal batteries or 12V external d.c.

✩

COM connector for RS232

portable operation

or external 12V d.c.

. The built-in LCD

from

without

, the

will be decoded automatically by the ARD-2
and displayed on the LCD two lines at a time.

NAVTEX is easy too... select NAVTEX-E, tune
the AR5000 to a NAVTEX frequency (such as
518 kHz), select SSB... and a whole new world
opens up. Changing receive data mode is easy,
just press one of the four mode keys:

[1] ACARS-1 mode (default) - airband ACARS
[2] ACARS-2 mode, raw data output, ideal for

computer control - airband ACARS

[E] NAVTEX-E English language - marine NAVTEX
[J] NAVTEX-J Japanese character set for use in the

coastal waters around Japan, requires connection to
an external PC which supports the Japanese

character set.

A built-in speaker with volume control allows
you to monitor activity and assess what is going
on, this is particularly useful for fine tuning of
NAVTEX and enables you to shut the sound off
completely when not required. A LEVEL control
provides threshold adjustment to achieve the
best capture of weaker signals for improved
differentiation between noise and data.

connection etc. A 9-pin
provided to enable

RS232

socket is also

connection to a computer

for improved comfort when viewing for extended
periods of time (Windows95TM Hyper-Terminal
may be easily configured), the RS232 connecting
lead is supplied with the ARD-2.

Don't get left behind... take a close look at the

ARD-2 today and enjoy the digital revolution.

Sockets are provided on the front and rear
panels for external speaker and earphone

What is ACARS...

ACARS which stands for Aircraft Communications Addressing and Reporting System is
a digital system transmitted over the VHF aircraft band around 131 MHz AM. Traffic is
handled by a computer network, in the USA Aeronautical Radio Inc (ARINC) are responsible
but in other countries different organisations are responsible. Not all aircraft are equipped
with ACARS but the mode is becoming more widely used.

Data does not simply comprise of text messages (although the request for tickets and
shower facility at airport terminals have been noted). A series of sensors on the aircraft
automatically collate information from the management unit and control units, these relate to
height, speed, outside temperature, wind, fuel, engine performance etc, this information
being transmitted by ACARS along with general positional data and more.

The ACARS data is processed into
transceiver on-board the aircraft checks the frequency before transmission to ensure that it
is clear then produces the short burst of data lasting less than one second.

Transmission takes place from air to ground (downlink) and from ground to air (uplink).
A flurry of data may be passed at take-off and landing (termed DEMAND MODE as it is
triggered by events) but positional transmissions may only occur occasionally, up to an hour
apart so it is best to catch transmissions close to a major airport or flight paths to and from.
General transmissions during flight (such as weather reports) may not be specifically
acknowledged at the time of transmission (to minimise congestion) but reception will be
acknowledged when the next transmission occurs.

Primary ACARS frequencies are: 131.550 MHz in the USA, Canada & Pacific (secondary
being 132.025, 129.125 MHz), 131.450 MHz in Japan and 131.725 MHz in Europe.

For transmission efficiency, many abbreviations and codes are used. Further reading is
recommended by book or internet:

Understanding ACARS by Ed Flynn, Copyright Fred Osterman and published by
Universal radio Research, 6830 Americana Pkwy. Reynoldsburg, Ohio 43068, USA.
ISBN 1-882123-36-0

ACARS-Link, About ACARS http://www.grove.net/~acarslink/alabout.htm

Sample of typical abbreviations used by ACARS:

AL (or FL) Flight level
CZ Cruising speed
DP Dew point
HD Heading
WX Weather
ADF Automatic direction finding
ALT Altitude
CPT Captain
ENG Engine data
FOB Fuel on board
GND Ground
OAT Outside air temperature
TRB Turbulence
POSWX Position weather
WXRQ Weather request

packets

of serial data for efficient handling. The

What is NAVTEX...

NAVTEX which stands for NAVigational TelEX is a well organised international digital system
transmitted over the short wave bands.

Coastal stations regularly broadcast traffic lists of names of ships for which it holds
messages, weather reports etc. This automated system now enables marine traffic to
log on to a coastal stations mailbox and download its data without human intervention.

Each transmission is coded by category and station identified by a four character group
at the start of the transmission B(1) B(2) B(3) B(4).

B1 Station identifier
B2 Subject of message
B3 & B4 Message type

Example of B1:

When geographically separated, the same letter may be allocated to more than one coastal
station without any problems occurring.

Example of B2:

It is possible for shipping to program what will be received and what will not, certain
categories of urgent transmission cannot be locked out.

Primary NAVTEX frequencies are 518 kHz and 424 kHz but other frequencies are used.
In the coastal waters around Japan NAVTEX-J may be encountered where Japanese
characters may be decoded by the ARD-2 and displayed on a PC which supports this
character set.

For transmission efficiency, many abbreviations and codes are used. Further reading is
recommended by book or internet:

http://www.navcen.uscg.mil/marcomms/gmdss/navtex.htm

G Cullercoats, UK
S Niton, UK
R Reykjavik, Iceland

A Navigational warnings
B Meteorological warning
C Ice reports

®

AOR Ltd

2-6-4 Misuji, Taito-ku, Tokyo 111, Japan

Tel: [phone] Fax: [phone]

e-mail: [e-mail] www.aorja.com

AOR (UK) Ltd
AOR Manufacturing Ltd

4E East Mill, Bridgefoot, Belper, Derbys DE56 2UA, England

Tel: [phone] Fax: [phone]

e-mail: [e-mail] www.demon.co.uk/aor