R.V.R. Elettronica TRDS 4001, User Manual

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TRDS 4001
7 / 36 User Manual Rev. 4.0 - 23/03/01
4. General Description
4.1 Introduction
The necessity to immediately know the working parameters of several device in a
system or to transmit with all the several units which have to manage a firm, is a
more and more greater need in all circles.
The cordless broadcasting , for its simple installation and its great pliability, appears
as the more suitable solution in many circles.
In the broadcasting field too, the need to transmit not only the radio signals, but
also data package of different kinds, is already strongly felt for many years, because
it allows to better the quality and the reliability of the available services and at the
end to implement the new ones.
This necessity is also felt in the international field, so much that a proper research
team has constituted itself to identify the different necessities and to determine a
broadcasting standard which would appear more proper for the sector.
The team has reached the "RADIO-DATA-SYSTEM (RDS)", which appears todays
the data broadcasting system more used in the radio field.
The TRDS4001 system allows to transmit, with the radio signal (mono or stereo),
a data channel as specified in the paper "Specification of the radio data system
(RDS)", which is issued by the European Committee for Electrotechnical
Standardization (CENELEC) Ref. N° EN 50067.
4.2 RDS System Description
The RADIO-DATA-SYSTEM is proper for the transmission of information in mono/
stereo programs of VHF/MF (87.5-108 Mhz).
It satisfies the requested requirements to the transmission of supplementary data
on radio programs:
1) Compatibility with the current mono/stereo transmissions;
2) Absence of interferences towards the adjacent programs;
3) Compatibility with other identification systems which are already working.
The system, selected by an international specialistic team, allows the data
transmission at a speed of 1187.5 bit/sec with phase modulation at two levels ,
carrier wave 57 Mhz and range ±2 Khz.
The broadcasted binary signal is in advance put out on a differential codification.