Comtech EF Data CDM-600 Installation And Operation Manual page 75

CDM-600 Satellite Modem
Front Panel Operation
CONFIG: TX: DATA
TX DATA RATE = 01544.000 kbps
DATA INVERT = OFF (ON,OFF)
The top line permits the data rate to be edited. Select the digit of Transmit Data Rate to
be edited using the [←] [→] arrow keys. The value of the digit is changed using the [↑]
[↓] arrow keys. Press ENTER.
NOTE: The minimum and maximum data rates are dependent on Modulation type and
FEC encoder 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 Drop 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.
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 information on how to connect the cables for the
AUX data rates.
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.
CONFIG: TX: SCRAMBLER
TX SCRAMBLER = ON (ON,OFF)
Select either ON or OFF, using the [↑] [↓] arrow keys, then press ENTER.
The choice of scrambler is selected automatically, and will be depend on the exact
operating mode. For example, if no framing is being used, the ITU V.35 scrambler
(Intelsat variant) will be used. If IBS framing is selected, the IESS-309 scrambler will be
used, etc. If Turbo encoding is used a second scrambler selection is available: IESS-315
V.35 instead of the TPC scrambler.
TX SCRAMBLER = IESS (NORMAL,IESS,OFF)
If LDPC encoding is selected the standard ITU V.35 scrambler will be used.
FRAME SCRAMBLER
IESS-315 V.35 SCRAMBLER
6–13
Revision 7
MN/CDM600.IOM