Kathrein UFS 740sw - Manual (Page 84)

84
SHORT TECHNICAL GUIDE
DISEQC™
DiSEqC™ (Digital Satellite Equipment Control) is a communication system between a satellite receiver
(master) and the peripheral satellite components (slaves), such as LNBs, multi-switches, rotating antenna
systems.
It is a single master/multi-slave system, i.e. there is only ever one master in the satellite system. All
activities start from the master.
DISEQC™ COMPONENTS
If DiSEqC™ switching matrices are cascaded, the master receiver must transmit the DiSEqC™ signal
several times, so that all DiSEqC™ multi-switches in the cascade receive their commands.
These days, DiSEqC™ components (slaves) must be reverse compatible, i.e. respond to the analogue
switching criteria from receivers that are only equipped with H/V and 22 kHz control signals.
A DiSEqC™ switching matrix will work with analogue switching criteria until the DiSEqC™ command from
the master is received. All analogue switching criteria are then ignored.
DVB MPEG-2
DVB is the abbreviation for Digital Video Broadcasting. DVB-S refers to the transmission method
(S = satellite). MPEG is the abbreviation for Moving Picture Experts Group, a working group that
formulates internationally applicable standards for the digital compression of video and audio. MPEG-2 has
established itself as the standard for compression of digital TV signals. MPEG-2 works up to a data rate
of 100 Mbit/s.
EB/NO RATIO
The Eb/No ratio is a measure of the signal to noise ratio of a digital signal. The value is not identical to
the C/N value familiar from analogue reception technology. At Eb/No values below 5 dB no reception is
normally possible.
FEC
FEC is the abbreviation for Forward Error Correction. The FEC error rate corresponds to the Viterbi rate.
CHANNEL PACKAGE
The channel package for a digital transponder normally includes several TV and radio channels.
Each channel package has a fi
xed assignment for the transponder transmission frequency, for
polarisation (horizontal or vertical), for the symbol rate and for the Viterbi rate or error rate.