Q-Flex Satellite Modem Installation and Operating Handbook
7-5
Modem Rx
Data Interface
Rx Buffer
DDS
VCXO
Rx Data
Rx Clock (RT)
PLL
Data from
decoder/deframer
Tx Data I/F
Tx FIFO
Tx Clock (TT)
Figure 7-5 Tx Clock In Rx Clock Mode
7.1.2.3 Station Clock
When
Station
is selected, the modem’s Rx timing is phase-locked to the station clock
input but is run at the Rx data rate frequency. The Rx Doppler buffer is enabled. The
clock and data appear on RT (Receive Timing) and RD (Receive Data) respectively. The
station clock input can be configured to provide a clock just for Rx path processing or it
can be used to replace the modem’s internal 10MHz clock (used for all internal
processing). The station clock frequency need not equal the modem’s internal 10MHz
clock frequency when it is being used to provide just Rx path clocking: it can be set
anywhere between 1kHz and 10MHz.
Modem Rx
Data Interface
Rx Buffer
DDS
Rx Data
Rx Clock (RT)
Data from
decoder/deframer
Station clock
Figure 7-6 Station Clock Rx Clock Mode
