Comtech EF Data CDM-700 - Manual (Page 74)

CDM-700 High Speed Satellite Modem Revision 5
Front Panel Operation MN/CDM700.IOM
6–20
Composite Data Rate = ∑ Port-Data Rates, where:
Ports = all enabled ports for Intfc1 and Intfc2 and depends upon the interfaces
installed in Slot 1 and Slot 2.
Symbol Rate = 1.025 *Composite Data Rate /(m *CR), where:
m = the modulation index (2 for QPSK, 2 for 8-PSK, 4 for 16-QAM, 5 for
32-QAM, 6 for 64-QAM),
and
CR = Code Rate (3/4, etc)
Press
ENTER
or
CLEAR
to return to the previous menu.
Rx: Æ Sym
Rx Sym Rate:
34.368000 Msps (E)
This is a ‘read only’ status window that displays the Symbol Rate. Refer to the detailed
explanation provided under (CONFIG:) Rx Æ Data.
The symbol rate shown in this example is for a composite data rate of 34.368 Mbps (E3) when
the modulation is QPSK and the code rate is 3/4.
Press
ENTER
or
CLEAR
to return to the previous menu.
Rx:
Æ Descrm
Descrambling: Default-On
Off (E)
Options are:
Default-On The proprietary descrambler is selected.
Off No Descrambling.
The options are displayed all of the time, but the ◄ ► arrow keys will force the cursor to skip
past an unavailable choice. Press
ENTER
.
Rx:
Æ Eb/No
Eb/No Alarm: Threshold
Alarm/Fault (E)
Select Threshold or Alarm/Fault using the ◄ ► arrow keys. Press
ENTER
.