Config: Tx  Scrambler; Config: Rx - Comtech EF Data CDM-625A Installation And Operation Manual

CDM-625A Advanced Satellite Modem
Front Panel Operation
6.2.1.3.8 CONFIG: Tx  Scrambler
Tx Scrambler = IESS (Normal,IESS,Off)
Use the arrow keys to select Normal, IESS, or Off, and then press ENTER.
▲▼
The modem automatically selects the actual scrambler used for Normal, depending on the exact
operating mode:
•
If framing = IBS/D&I, the IESS-309 scrambler is used.
•
If Reed-Solomon is on but IBS/D&I is off, its frame synchronous scrambler is used per
IESS-310, App. H. An exception to this is legacy EF Data Reed-Solomon, which uses a
proprietary modified V.35 scrambler instead.
•
If framing = EDMAC/2/3 and Reed-Solomon is off, its frame synchronous scrambler is
used.
•
If configured for TPC (Turbo) encoding and all of the above settings are off, the TPC
frame scrambler is used except for 8-QAM. For CDM-570 compatibility, TPC with 8-QAM
uses the V.35 scrambler.
•
ITU V.35 scrambler (Intelsat variant) is the default scrambler when all of the above
settings are off.
When selecting IESS, the default ITU V.35 scrambler specified in IESS-315 takes priority over all
"normal" scramblers and is used instead. Therefore, for many operating modes, the two
scrambler choices are redundant.
When using TPC and Carrier-in-Carrier simultaneously, the IESS-315 (V.35) scrambler is the only
permitted choice.
6.2.1.4

CONFIG: Rx

RxIF Freq FEC Demod Data Descram Eq EbNo
(Data 02048.000kbps,02184.533ksps) ()
On the top line – Use the
IP-ACM Mode), Descram, Eq, or EbNo, and then press ENTER.
On the bottom line – Read-only Data/Symbol rate information is provided.
When Sub-Mux is ON, the Data Rate information on the bottom line of this display
is replaced by Composite Rate information.
IESS-315 V.35 Scrambler
◄ ► arrow keys to select RxIF, Freq, FEC, Demod, Data (Symb when in
6–22
Revision 0
MN-CDM625A
()