Comtech EF Data CDM-700 - Manual (Page 66)

CDM-700 High Speed Satellite Modem Revision 5
Front Panel Operation MN/CDM700.IOM
6–12
6.3.1.2 (CONFIG:) Tx
Tx: Mod Code Freq Data
Sym Pwr Scram (E)
The modem symbol rate is a function of the modulation type, code rate, and data rate. If a change
to one of these parameters produces a value outside the allowable symbol rate range, the invalid
symbol rate is not programmed into the modem.
For example: If the data rate is increased at one of the interfaces and the symbol rate exceeds the
limit it is possible that changing the modulation type or code rate will bring the symbol rate
within range.
IMPORTANT
All possible choices are presented at all times, If an option is not installed
(either Hardware or FAST) or valid, the ◄►arrow keys will force the cursor to
skip past the unavailable choice.
Tx: Æ Mod
Tx Modulation: Type Inv
α (E)
Select Type, Inv, or α using the ◄ ► arrow keys. Press
ENTER
.
If Tx Modulation Æ Type is selected:
Tx Mod: Q 8P 16Q 64Q
(E)
Select the Transmit Modulation Type by using the ◄ ► arrow keys. Press
ENTER
. The choices
are as follows:
Modulation Type (Symbol Rate) Selection Description
Q (QPSK) Valid for all FEC types
8P (8-PSK) Valid for all FEC types
16Q (16-QAM) Valid for all FEC types
64Q (64-QAM) Valid for all FEC types