Mocomtech CDM-QX - Manual (Page 121)

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision 7
Front Panel Operation MN/CDMQX.IOM
5–55
5.7.3 INFO: Rx
Rx: 1140.000 05000.000 TUR
8P 17/18 D RX BUF +/-32k N ▲▼
This screen provides Receive Configuation Information. Per this example, note the following:
Top Line
• 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)
Bottom Line
• 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)
Use the ST arrow keys to display this second page of information:
Rx: C N N 35
▲ ▼
Per this example, note the following:
Top Line
• 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)
Bottom Line ▲▼ Page navigation mnemonic
5.7.4 INFO: Buffer
Buffer: Enabled (Tx=Rx)
(ENT)
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).