Comtech EF Data SDM-650B Installation And Operation Manual page 113

SDM-650B Satellite Modem
BBLoopBk
(Test Mode Configuration
Option)
Scramblr
Dscrmblr
DifEncdr
TX_Clock
RX_Clock
SWP_RACQ
Rev. 5
Programs the modem for baseband loopback operation.
When baseband loopback is turned ON, the data and timing signals are
hard-wired (relays) from the demodulator to the modulator. The DTE
baseband signals are also looped back from transmitter data and clock,
to receiver data and clock.
On entry, the current status of the baseband loopback is displayed with
the flashing cursor on the first character. Use the arrow keys to select
ON or OFF. Press [ENTER] to execute the change.
Programs the modulator for scrambler ON or OFF.
On entry, the current status of the scrambler is displayed with the
flashing cursor on the first character. Use the arrow keys to select ON
or OFF. Press [ENTER] to execute the change.
Programs the demod/decoder for descrambler ON or OFF.
On entry, the current status of the descrambler is displayed with the
flashing cursor on the first character. Use the arrow keys to select ON
or OFF. Press [ENTER] to execute the change.
Programs the differential decoder ON or OFF.
On entry, the current status of the differential decoder is displayed with
the flashing cursor on the first character. Use the arrow keys to select
ON or OFF. Press [ENTER] to execute the change.
Programs the modem for internal or external transmitter clock.
On entry, the current status of the TX clock is displayed with the flashing
cursor on the first character. Use the arrow keys to select Internal or
External transmit clock. Press [ENTER] to execute the change.
Programs the modem for inverted or normal receive clock.
On entry, the current status of the RX clock is displayed with the
flashing cursor on the first character. Use the arrow keys to select
Inverted or Normal receive clock. Press [ENTER] to execute the
change.
Programs the sweep re-acquisition mode time duration.
The time that is selected with this parameter is the time that the modem
will remain in a narrow sweep (± 10%) after acquisition has been
accomplished. After this timer runs out, the modem will return to the
normal sweep.
On entry, the current programmed setting is displayed with a flashing
cursor on the first character. Use [
cursor. Use [ ↑ ] and [ ↓ ] to increment and decrement the digit at the
flashing cursor. Select the number of seconds for the re-acquisition
mode from 0 to 999 seconds. Press [ENTER] to execute the change.
← ] and [ → ] to move the flashing
Operation
4–11