Comtech EF Data CDM-600 Operating Instructions Manual page 66

CDM-600 Satellite Modem
Front Panel Operation
NOTE: The minimum and maximum data rates are dependent on Demodulation type and
FEC decoder Rate. If the user changes the Modulation or FEC, and the data rate becomes
invalid, the Data Rate will be adjusted automatically. The upper range of data rate will
be dictated by the FAST option installed.
When Insert Framing or the G.703 interface type is used the [↑] [↓]arrow keys will scroll
through the available data rates. If in Drop Mode and the data rate is edited to 1920 kbps,
a comment is shown to indicate that E1 fixed channel mode will be implemented. The
bottom line permits the user to select the data inversion feature (added for compatibility
with certain older equipment). Select either ON or OFF, using the [↑] [↓] arrow keys,
then press ENTER.
When G.703 is used and the Modem is Hardware Revision 2.0 or higher, three auxiliary
rates will also be available (512, 1024, and 2048 kbps) indicated by the word AUX
appearing to the right of the decimal place. (For example, 00512.AUX kbps).
Refer to Section 4.3 IDI/DDO connectors for additional information about how to
connect the cables for the new AUX data rates.
The bottom line permits the user to select the data inversion feature (added for
compatibility with certail older equipment). Select either ON or OFF, using the [↑ ] [↓]
arrow keys, then press ENTER.
CONFIG: RX: DESCRAMBLER
RX DESCRAMBLER = ON (ON,OFF)
FRAME DESCRAMBLER
Select either ON or OFF, using the [↑] [↓] arrow keys, then press ENTER.
The choice of descrambler is selected automatically, and will be depend on the exact
operating mode. For example, if no framing is being used, the ITU V.35 descrambler
(Intelsat variant) will be used. If IBS framing is selected, the IESS-309 descrambler will
be used.
If Turbo decoding is used a second scrambler selection is available: IESS-315 V.35
instead of the TPC scrambler.
RX DESCRAMBLER = IESS (NORMAL,IESS,OFF)
If LDPC decoding is selected the standard ITU V.35 descrambler will be used.
IESS-315 V.35 DESCRAMBLER
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Revision 7
MN/CDM600.IOM