Comtech EF Data CDM-600L, Инструкция по установке и эксплуатации

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CDM-600L Satellite Modem Revision 0
Front Panel Operation MN/CDM600L.IOM
6–14
CONFIG: RX: DECODER
Select the parameter to edit using the [
←
] [
→
] arrow keys.
The Decoder options are shown in the parentheses. Select using the [
↑
] [
↓
] arrow keys,
then press ENTER. The choices are:
•
Viterbi
•
Sequential
•
Trellis Coded Modulation - 8-PSK Rate 2/3 only (FAST option)
•
Turbo (Hardware option)
•
None (uncoded)
Select ON or OFF for Reed-Solomon using the [
↑
] [
↓
] arrow keys, then press ENTER. If
Reed-Solomon is ON, proceed to the next menu. If NONE is selected, the bottom line of
the display will change from the R-S selection to the Differential Encoding selection, as
shown below:
IMPORTANT
If the user selects Differential Decoding = OFF, there is no way for the
modem to resolve the phase ambiguities associated with PSK
modulations. For BPSK there is a 1 in 2 chance that the polarity of the
data will be correct. In QPSK there is a 1 in 4 chance that the data will
be correct.
CONFIG: RX: DECODER: REED-SOLOMON ON
Use the [
↑
] [
↓
] arrow keys to select one of the listed parameters, and press ENTER.
Selections depend on the Framing mode. Possible selections include:
•
IESS-310 (219/201), open or closed network
•
IBS (126/112), open or closed network
•
EDMAC (200/180), closed network
•
IDR (225/205), open network
•
IDR (194/178), open network
•
UNFRAMED (220/200), closed network
•
LEGACY COMTECH EF DATA (225,205, with V.35 scrambling), closed network
DECODER = VIT (NONE,VIT,SEQ,TCM,TURBO)
REED-SOLOMON = OFF (ON,OFF)
REED-SOLOMON DECODING = ON(200/180)
DECODER = NONE (NONE,VIT,SEQ,TCM,TURBO)
DIFF-DECODER= OFF (ON,OFF)