Info: Rx; Info: Buffer - Comtech EF Data CDM-Qx Installation And Operation Manual

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier®
Front Panel Operation
5.7.3

INFO: Rx

Rx: 1140.000 05000.000
8P 17/18 D RX BUF +/-32k
This screen provides Receive Configuation Information. Per this example, note the following:
Top Line
Bottom Line
Use the arrow keys to display this second page of information:
Rx: C N N 35
Per this example, note the following:
Top Line
Bottom Line
5.7.4

INFO: Buffer

Buffer:
This screen provides Buffer Information. It displays if the buffer is Enabled or Disabled and
shows the exact clocking mode (TX=RX, or TX<> RX).
•
1140.000 05000.000 = Receive Frequency and Data Rate (NOTE: Due to
space limitations, the resolution of displayed frequency is limited to 1 kHz, and
data rate to 10Hz)
•
TUR = FEC Decoder type (VIT = Viterbi, SEQ = Sequential, VRS=Viterbi +
Reed-Solomon, SRS=Sequential + Reed Solomon, TCM = Trellis Coded +
Reed-Solomon, TUR = Turbo)
•
8P = Demodulation type (Q = QPSK, B = BPSK, 8P = 8-PSK, 16=16-QAM)
•
17/18 = Code Rate (2144 = 21/44, then 5/16, 1/2, 2/3, 3/4, 7/8, 17/18)
•
D = Descrambler state (D = Descrambler on, N = Descrambler off)
•
RX = Buffer Source (IN = internal, RX = Rx satellite, TT = Tx terrestrial)
•
BUF = Buffer Clocking Mode (SAT = buffer disabled, BUF = buffer enabled)
•
+/-32k = Demod Sweep Acquisition range
•
N = RSI state (I = Receive Spectral Inversion on, N = off)
•
C = Reed-Solomon code rates (C=Comtech (220,200), E=EF Data (225,205),
I=IESS-310 (219,201)
•
N = Rx Clock Inversion (N=Normal, I=Inverted)
•
N = Rx Data Inversion (N=Normal, I=Inverted)
•
35 = Rx Roll-Off (α) factor (20=20% roll-off, 35=35% roll-off)
▲▼ Page navigation mnemonic
Enabled (Tx=Rx)
(ENT)
TUR
N ▲▼
▲ ▼
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Revision 7
MN/CDMQX.IOM