Comtech EF Data CDM-570 - Manual (Page 99)

CDM-570/570L Satellite Modem with Optional IP Module Revision 12
Front Panel Operation MN/CDM570L.IOM
5–13
change the modulation type from QPSK to 16-QAM. In this case, Rate 1/2 is no
longer a valid code rate, and so it will be automatically changed to the nearest valid
code rate (Rate 3/4).
5.2.2.1.3.1 (CONFIG: Tx) FEC (FEC Type)
Tx FEC: Viterbi Vit+RS
TCM+RS TPC Uncoded
IMPORTANT NOTE: All available 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.
CASE RULES COMMENT
Viterbi ALWAYS VALID
Vit+RS
(Viterbi +Concatenated Reed-Solomon)
If the RS codec is installed
TCM+RS
(Trellis Coded Modulation +
Concatenated Reed-Solomon)
If the RS codec is installed
AND 8-PSK FAST is enabled
Fixed at 8-PSK and Rate 2/3
TPC
(Turbo Product Codec)
If the TPC codec is installed
Uncoded
Always valid - BPSK, QPSK and
OQPSK only.
Forces Code Rate to 1:1 (uncoded)
5.2.2.1.3.2 (CONFIG: Tx) Mod (Modulation)
Modulation: BPSK QPSK
OQPSK 8-PSK 16-QAM 8-QAM
IMPORTANT NOTE: All available 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.
CASE RULES
BPSK Valid for all FEC types except TCM+RS
QPSK Valid for all FEC types except TCM+RS
OQPSK Valid for all FEC types except TCM+RS
8-PSK Requires TCM+RS OR Turbo codec AND requires 8-PSK/ 8-QAM FAST option
8-QAM Requires Turbo codec AND requires 8-PSK/8-QAM FAST option
16-QAM Requires Viterbi+RS OR Turbo codec AND requires 16-QAM FAST option