Q-Lite Satellite Modem Installation and Operating Handbook
7-3
Modem Tx
Data Interface
FIFO
DDS
PLL
VCXO
TCXO
Tx Data Tx Clock (TT) Internal Tx Clock (ST)
Figure 7-2 External Tx Clock Mode
7.1.1.3 Receive Reference
When
Receive Reference
is selected, it allows the modem to provide an ST clock to the
DTE that is locked to the receive satellite signal. The timing is actually phase locked to
the Rx data rate but at the frequency of the Tx data rate. This is to allow asymmetric
operation. The DTE then synchronises the data going into the modem (SD) to this clock.
If the external clock is missing for any reason then the modem will substitute an internal
clock.
Modem Tx
Data Interface
FIFO
DDS
PLL
VCXO
VCXO
Tx Data Tx Clock (TT) Internal Tx Clock (ST)
PLL
Rx Clk
Figure 7-3 Receive Reference Tx Clock Mode
Содержание Q-Lite
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Страница 146: ...Q Lite Satellite Modem Installation and Operating Handbook 6 113 6 4 2 Status Menu Figure 6 64 Front panel Status Menus ...
Страница 147: ...Q Lite Satellite Modem Installation and Operating Handbook 6 114 6 4 3 Edit Menu Figure 6 65 Front panel Edit Menus ...
Страница 233: ...Q Lite Satellite Modem Installation and Operating Handbook 12 11 Figure 12 2 PER for DVB S2 Short Frames ...
Страница 234: ...Q Lite Satellite Modem Installation and Operating Handbook 12 12 Figure 12 3 PER for DVB S2X Normal Frames ...
Страница 235: ...Q Lite Satellite Modem Installation and Operating Handbook 12 13 Figure 12 4 PER for DVB S2X Short Frames ...
Страница 237: ...Q Lite Satellite Modem Installation and Operating Handbook 12 15 12 14 4 DVB S DSNG Figure 12 7 BER for DVB S DSNG ...