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Short Technical Guide
Short Technical Guide
DiSEqC™
DiSEqC™ components
DVB MPEG-2
EB/NO ratio
FEC
OTR
PID
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.
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 critiera
until the DiSEqC™ command from the master is received. All
analogue switching criteria are then ignored.
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.
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 is the abbreviation for Forward Error Correction. The FEC error
rate corresponds to the Viterbi rate.
One Touch Recording
The PID (Packet IDentification) number is an identification number for
video signals and audio signals in the digital data stream of DVB-
MPEG-2 signals. The receiver uses the PID number to create a
unique assignment for the video and audio data transmission. The
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