— 5 —
Section II
THE RADIO DATA SYSTEM
What is RDS, Anyway?
RDS is a digital data channel transmitted as a low-level,
double-sideband, suppressed-carrier ‘subcarrier’ at 57kHz.
The data transmission rate is a modest 1100 baud, but
transmission is quite robust, thanks to data redundancy
and error correction algorithms.
It is not within the scope of this Manual to offer a tutorial
on RDS coding and modulation details. For this, see either
the CENELEC EN50067 or the corresponding United States
NRSC Standard. The balance of this Manual deals specifical-
ly with RDS implementation afforded by the Inovonics 703
encoder.
US vs. Europe
The European Broadcasting Union (EBU) and its member
countries developed the concept of transmitting data along
with commercial radio broadcasts. The first European RDS
specification was published in 1984 and has been revised
several times since.
Following its initial introduction, RDS quickly grew in use
throughout Europe. By the late 1990s it was hard to find a
European FM station
without
a radio data subcarrier.
The popularity of RDS in Europe reflects a ‘network’ ap-
proach to broadcasting that is still practiced in many coun-
tries. A disposition toward large numbers of lower-power
transmitters to blanket a designated service area can be
found both at the national network and ‘local radio’ levels.
The European concept of a
service area
equates to a US
broadcaster’s
market
. The semantic difference between
these designations further delineates broadcasting practic-
es. RDS benefits the European broadcaster through an al-
truistic endeavor to be of
service
to his listeners. The US
broadcaster is
marketing
his programming, and is more
concerned in how he can make additional profit from RDS
and other subcarriers.
— 6 —
Section III
INSTALLATION AND SETUP
Unpacking and Inspection
Immediately upon receipt of the equipment, inspect for
possible shipping damage. If damage is found or suspected,
notify the carrier at once, and then contact Inovonics.
We recommend that you set aside the original shipping car-
ton in case return for Warranty repair is required. Shipping
damage sustained as a result of improper packing for re-
turn may invalidate the Warranty!
Warranty Registration
It is important to complete and return the Warranty Regis-
tration Card included with this Manual, or to register the
Warranty online at www.inovon.com. Not only does regis-
tration assure coverage of the equipment under terms of
the Warranty (posted inside the back cover), but the user
may automatically receive specific service and modification
instructions, including any software or firmware updates.
Mounting
The Model 703 RDS encoder is packaged in a compact
‘clamshell’ chassis that represents the standardized Inovon-
ics’
INO
mini
module. The 703 may simply be set on top of
an existing piece of rack-mounted equipment, as long as at
least 1U of panel space is left open
above
the rack-mounted
‘host’ to access the encoder. Alternatively, a pair of mount-
ing holes on the chassis base allow the 703 to be fastened
to the inside of an equipment rack cabinet with two screws.
An optional rack-mount kit is available for the 703, which
can house up to three
INO
mini
modules. The kit comes with
blanking panels for unused spaces.
AC Mains Power
The Model 703 is supplied with an outboard switching-type
power supply suited to the destination mains voltage. As
the actual power consumed to the encoder is 12 volts DC at
150mA, a second DC connector on the rear panel of the 703
