Datum Systems M7LT Series - Page 105

M7/M7L/M7LT Modular Satellite Modem Maintenance
M7/M7L/M7LT - Rev. 0.05 3-49
Demodulator Parameters
Representation
Type
Entry
Description
Data Descrambler
Auto
Selection
0 = Disable,
1 = Auto
2 = V.35,
3 = Intelsat,
4 = EFD,
5 = Alt V.35
6 = Alt Intelsat
7 = Alt RS EFD**
8 = RS Sync**
(Vit + R-S) Descrambler types.
Types are added if optional
hardware is installed. The Auto
mode uses IESS standards to
automatically switch to use
synchronous scramblers part of
R-S and TPC.
** only when R-S = Enabled
Data FEC Option
Advanced
Selection
0 = Advanced,
1 = CT,
(TPC) Sets the compatibility
mode for the TPC FEC decoder
Data FEC Code Rate
3/4-4k
Selection
0 = 0.452-16k,
1 = 1/2-16k, 2 = 1/2-4k
3 = 3/4-16k, 4 = 3/4-4k
5 = 7/8-16k, 6 = 7/8-4k
7 = 0.922-16k,
8 = 0.950-4k
(TPC) Sets the code rate of the
TPC FEC decoder.
Data Descrambler
Auto
Selection
0 = Disable,
1 = Auto
2 = V.35,
3 = Intelsat,
4 = EFD,
5 = Alt V.35
6 = Alt Intelsat
7 = FEC Sync
8 = FEC Sync
(TPC) Descrambler types. Types
are added or removed
depending on the selected FEC
mode. The Auto mode uses
IESS standards to automatically
switch to use synchronous
descramblers part of R-S and
TPC.
Data FEC Option
4k Block
Selection
0 = 256 Block,
1 = 512 Block,
2 = 1k Block,
3 = 2k Block,
4 = 4k Block,
5 = 8k Block,
6 = 16k Block,
(LDPC) Sets the LDPC FEC
decoder block size
Data FEC Code Rate
3/4
Selection
0 = 1/2, 1 = 2/3,
2 = 3/4, 3 = 14/17,
4 = 7/8, 5 = 10/11,
6 = 16/17
(LDPC) Sets the code rate of the
LDPC FEC decoder.
Data Descrambler
Auto
Selection
0 = Disable,
1 = Auto
2 = V.35,
3 = Intelsat,
4 = EFD,
5 = Alt V.35
6 = Alt Intelsat
7 = FEC Sync
8 = FEC Sync
(LDPC) Scrambler types. Types
are added or removed
depending on the selected FEC
mode. The Auto mode uses
IESS standards to automatically
switch to use synchronous
scramblers part of R-S and TPC.
Data FEC Hold
1
Numeric
0 to 255
Normally set to 1
Number of FEC lock “cycles” the
FEC will accomplish before
declaring loss of lock.