Mocomtech CDM-QX - Manual (Page 120)

CDM-Qx/QxL Multi-Channel Satellite Modem with DoubleTalk™ Carrier-in-Carrier® Revision 7
Front Panel Operation MN/CDMQX.IOM
5–54
5.7.2 INFO: Tx
Tx: 1140.000 05000.000 TUR
8P 17/18 S EXT -20.0 ON N ▲ ▼
This screen provides Transmit Configuation Information. Per this example, note the following:
Top Line
• 1140.000 05000.000 = Transmit 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 Encoder type (VIT = Viterbi, VRS=Viterbi + Reed-Solomon, TCM =
Trellis Coded + Reed-Solomon, TUR = Turbo)
Bottom Line
• 8P = Modulation 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)
• S = Scrambler state (S = Scrambler on, N = Scrambler off, I=IESS-315)
• EXT = Clocking Mode (INT = internal, EXT = external, LOP = loop, ELP=external loop)
• -20.0 = Output Power level
• ON = (ON = on, OF = off, EO= external off)
• N
= TSI State (I = Transmit Spectral Inversion on, N = off)
Use the ST arrow keys to display this second page of information:
Tx: 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 = Tx Clock Inversion (N=Normal, I=Inverted)
• N = Tx Data Inversion (N=Normal, I=Inverted)
• 35 = Tx Roll-Off (α) factor (20=20% roll-off, 35=35% roll-off)
Bottom Line ▲▼ Page navigation mnemonic