Comtech EF Data DD240XR Rev Е User Manual

Page 26

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User Interfaces

DD240XR High-Speed Digital Demodulator

4-6

MN-DD240XR – Rev. E

SAT FRAMING

FECFRAME

Select NORMAL n_ldpc = 64,800 or

SHORT n_ldpc = 16,200


DATA RATE (bps):

Terrestrial Data Rate:

Enter in 1 bps increments from 2,000,000 to 160,000,000
BPS.


SYMB RATE (sps):

Output Symbol Rate:

Enter in 1 sps increments from 2,000,000 to 45,000,000
sps.


SPECTRUM:

{AUTO DETECT}

This is the commanded spectrum detection. Select
NORMAL or INVERTED. This display is not user
selectable for DVBS 8PSK or 16QAM, where it is fixed
as AUTO DETECT.


ROLL OFF:

DVB-S: {0.20, 0.35} for QPSK/8PSK/16QAM.
DVB-S2 {20, .25, .35} for QPSK/8PSK/16APSK


PILOT SYMBOLS:

{ON, OFF}

Used to enable pilot symbol for DVB-S2 only


GOLD SEQ N:

{012345}

Gold code sequence number for DVB-S2 only


LAST RATE CTRL:

{SYMBOL RATE, DATA RATE, AUTO}

Indicates the rate (symbol or data) which is maintained
when associated parameters (i.e. Modulation, Inner FEC
Code Rate, Terr Framing) are changed. For example, if
the Last Rate Control is set to “Symbol Rate” and the
modulation is subsequently changed, the system will
attempt to maintain the same symbol rate by adjusting
the data rate. If the Last Rate Control is set to “Data
Rate” and the modulation is subsequently changed, the
system will attempt to maintain the same data rate by
adjusting the symbol rate.

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