Comtech EF Data SDM-9000 - Manual (Page 125)

Operation SDM-9000 Satellite Modem
4–52 Rev. 4
BASEBAND
TX DATA/CLOCK
TERRESTRIAL
RX DATA/CLOCK
TX DATA
RX DATA
MODULATOR
DATA
DEMODULATOR
DATA
MODULATOR
MODULE
DEMODULATOR
MODULE
INTERFACE
MODULE
TX IF OUT
RX IF IN
Baseband loopback provides loopback at the
terrestrial interface. The near end equipment
loops back through the baseband loopback
relays. The far end equipment loops through
the demodulator, interface, and the modulator.
DATA/CLOCK
LOOPBACK
RELAYS
Figure 4-19. Baseband Loopback
Interface loopback provides loopback at the interface
between the interface module and the modulator/demodulator.
The near end equipment loops through the interface module.
The far end equipment loops through the modulator/demodulator.
TX DATA/CLOCK
TERRESTRIAL
RX DATA/CLOCK
TX DATA
RX DATA
MODULATOR
DATA
DEMODULATOR
DATA
MODULATOR
MODULE
DEMODULATOR
MODULE
INTERFACE
MODULE
TX IF OUT
RX IF IN
INTERFACE
LOOPBACK
MUX
DATA/CLOCK
Figure 4-20. Interface Loopback