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Note: The 1st Generation DVB-S2 option is limited to 31 MSyms (or 81 Mbps) in
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Note:
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Notes: A license key is required to enable DVB-S2 and DVB-S2X functionality
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EN/LZT 790 0005 R7A
Symbol Rate – This field should be entered with the symbol rate of the wanted
signal. In DVB-S2 mode, a Low Symbol Rate license is required to enable 1 –
5 MSyms operation. Where the DVB-S2X card is fitted, this license is not
required.
DVB-S2 mode whereas the 2nd Generation DVB-S2 card has a higher
symbol rate limit of 60 MSyms (or 170 Mbps). The DVB-S2X card is limited
to 54 MSyms.
Search Range – Owing to frequency inaccuracies of the transmission system
(mostly LNB inaccuracies) the wanted carrier may not be exactly on frequency.
This option provides the satellite input with the maximum frequency search limits
within which to attempt to acquire the wanted signal. A typical search range is
5000 kHz. A narrower search range may result in faster acquisition especially for
low symbol rate carriers.
For low symbol rate transmissions, a search range that is too wide may
cause the IRD to lock onto an unwanted, adjacent carrier. Care must be
taken to ensure that the search range entered is appropriate for the symbol
rate of the incoming carrier.
Gold Sequence / Physical Layer Scrambling – The gold sequence code is the
seed for a randomizing sequence which can be used to uniquely identify the
owner of the transmission. The satellite input will only lock to the incoming signal
when the gold code entered into the IRD matched the code set in the up-link
modulator. For this reason the Gold Sequence will often be used as a form of
fixed key CA.
Modulation Mode – Determines the modulation standard - DVB-S, DVB-S2 or
DVB-S2X. In DVB-S2/S2X mode, selection of the FEC rates (QPSK, 8PSK, etc.)
is automatic and does not require specific user entry.
depending on the type of satellite card fitted.
DVB-DSNG (EN301-210) 8PSK/16QAM modulation standard is not
supported by older generation satellite cards but is supported by the DVB-
S2X card.
The 1st Generation satellite input card and the DVB-S2X card has to be
explicitly set DVB-S or DVB-S2 mode whereas the 2nd Generation satellite
input card and Combined Satellite/IP card only present an automatic
detection option.
The DVB-S2X Input card can take up to 25 seconds to switch between
DVB-S and DVB-S2/S2X modes. This is because a different code image is
loaded in to the card for each mode.
FEC – Configures the modulation scheme and FEC Rate or MODCOD selection.
This option is exposed when the DVB-S2X card is fitted and must be explicitly
set in DVB-S mode, but can be set to AUTO for DVB-S2/S2X modes.
Using the Equipment
3-67
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