Comtech EF Data SDM-2020 - Manual (Page 74)

SDM-2020 Satellite Demodulator Revision 4
Front Panel Operation MN/SDM2020D.IOM
6–10
Function Select: Configuration: Demodulator: RX-SR
(Conditional)
RX-SR QPSK 1/2
(SYMBOL RATE)
Programs the demodulator symbol rate (SR), in 1 sym/s steps, limited by code rate and
data interface. On entry, the current symbol rate is displayed with the flashing cursor on
the first character. Press [
←] or [→] to move the flashing cursor. Press [↑] or [↓] to
increment or decrement the digit at the flashing cursor. Press to execute the
change.
Code Rate:
QPSK 1/2, 3/4, 7/8 5/6, 2/3
8PSK 2/3, 5/6, 8/9
16QAM 3/4, 7/8
1. Programming is done by either data rate or symbol rate. Data rate refers to the
equivalent serial data rate at the data interface connector.
2. Symbol rate refers to the modulation rate after framing, trellis (Viterbi) coding,
and Reed-Solomon coding are applied.
3. The framing type selection affects the symbol rate (if programming from the
data rate [RX-DR] menu), or the data rate (if programming from the symbol rate
[RX-SR] menu).
a. If data rate is programmed, the symbol rate menu is updated to reflect the
code rate and framing selections.
b. If symbol rate is programmed, the data rate display is similarly updated.