Config: tx, Datarate – Comtech EF Data SLM-5650A User Manual
Page 92
SLM-5650A Satellite Modem
Revision 8
Front Panel Operation
MN-SLM5650A
5–10
Option
Setting
Rate
•
Viterbi – 1/2, 2/3, 3/4, 5/6, or 7/8
•
Uncoded – 1/1
•
Turbo – 5/16, 3/4, 7/8, 17/18, or 21/44
•
Sequential – 1/2, 3/4, 7/8
•
ULL – 1/2, 2/3, 3/4
•
LL – .382, .456, .547, 1/2, 2/3, 3/4, 7/8
•
HP – 1/2, 2/3, 3/4
RS
Reed-Solomon Encoder: On or Off
Diff
Differential Encoder: On or Off
Scram
Scrambling (for energy dispersal):
V.35, MOD-V.35, IBS, TURBO, OM73, Synch, or Off.
Note the following:
•
V.35 – ITU standard.
•
MOD-V.35 (Modified V.35) – Comtech EF Data Closed Network with Reed- Solomon
compatible .
•
IBS – Used for IESS-309 operation.
•
Turbo – Synchronous scrambler synchronized to the Turbo block.
•
OM73 – Linkabit OM-73 modem compatibility mode.
•
Synch – Synchronous scrambler synchronized to the Reed-Solomon.
When changing modulation type, the data rate must be set to a rate supported
by the modulation type or the change to the modulation type will not be
allowed. Some choices will only be visible if the modem is set to a compatible
mode, or if an option is installed or enabled.
CONFIG: Tx
DataRate
Tx Data Rate: 020000.000 kbps
Sym Rate: 0266666.666 ksps(E)
Use Method 1 or Method 2 to enter the desired Tx Data Rate (in kilobits per second):
Method
Procedure
1
Use the number keypad and enter the desired data rate.
(See Appendix B. OPERATIONS GUIDE.)
2
Use the arrow keys to scroll through and select the desired data rate or symbol rate. When
scrolling through the data rates the symbol rate is automatically recalculated and displayed.
When entering the data rate, the following interactions need to be taken into
account:
If the modulation type selected is 8PSK, 8QAM, or 16QAM the minimum data
rate allowed is 256 kbps.
When changing certain parameters like modem type, the data rate will default to
64 kbps or 256 kbps.
The calculated symbol rate is displayed for the user. This is helpful for
determining the occupied bandwidth required for the selected modulation type,
code rate and overhead.