Comtech EF Data CDM-740 - Manual (Page 60)

CDM-740 Advanced Satellite Modem Revision 0
Front Panel Operation MN-CDM740
5–8
5.4.1.6 (CONFIG:) Tx Æ Data
Tx Data Rate: 9980.000 kbps
Tx Symbol Rate: 2851.429 ksps
( ◄► E)
To configure the Tx Data Rate (in kbps), on the top line select the digit of Data Rate to be edited
using the
◄ ► arrow keys, then change the value of that digit using the ▲ ▼ arrow keys. Press
ENTER when done.
The maximum limits for the Tx Data Rate are 16 kbps to 9.98 Mbps. The resolution is 1 bps.
The actual minimum and maximum data rates are dependent on Framing mode, Interface type,
Modulation type and FEC Code Rate. If the user changes any of the higher-priority parameters –
causing the data rate to become invalid – the Tx Data Rate is adjusted automatically. The upper
range of data rate will also be dictated by the FAST option(s) installed.
To configure the Tx Symbol Rate (in ksps), on the bottom line select the digit of Symbol Rate to
be edited using the ◄ ► arrow keys. Change the value of that digit using the
▲ ▼ arrow keys,
then press ENTER.
Refer to Table 5-1 for Tx Symbol Rate and Data Rate ranges (TPC).
Table 5-1. Tx Symbol Rate / Data Rate Ranges – TPC
Modulation FEC Code Code Rate
Symbol Rate (Ksps) Spectral
Efficiency
Data Rate (Kbps)
Min Max Min Max
QPSK Turbo
21/44 16.762 2996.190 0.955 16.000 2860.000
3/4 10.667 3000.000 1.500 16.000 4500.000
7/8 9.143
3000.000 1.750 16.000 5250.000
0.95 8.421 2982.105 1.900 16.000 5666.000
8-QAM Turbo
3/4 7.111 3000.000 2.250 16.000 6750.000
7/8 6.095 3000.000 2.625 16.000 7875.000
0.95 5.614 2982.456 2.850 16.000 8500.000
16-QAM Turbo
3/4 5.333 3000.000 3.000 16.000 9000.000
7/8 4.800 2851.429 3.500 16.800 9980.000
5.4.1.7 (CONFIG:) Tx Æ Scrambler
Tx Scrambler: Off Normal IESS
( ◄► E)
Select Off, Normal, or IESS using the ◄ ► arrow keys, then press ENTER. Note the following:
• When Normal is selected, the TPC scrambler is used.
• When IESS is selected, the default ITU V.35 scrambler specified is used.