Comtech EF Data SDM-650B - Manual (Page 112)

Operation SDM-650B Satellite Modem
4–10 Rev. 5
TX_Freq Programs the modulator transmit frequency between 50 and 90 MHz, or
between 100 and 180 MHz, in 2.5 kHz steps.
On entry, the current transmitter frequency is displayed with the flashing
cursor on the first character. Use [
← ] and [ → ] to move the flashing
cursor. Use [ ↑ ] and [ ↓ ] to increment or decrement the digit at the
flashing cursor. Press [ENTER] to execute the change.
Note: The transmitter frequency is programmable within the specified
range (50 to 180 MHz), in 2.5 kHz steps. When the transmitter
frequency is changed, the transmitter is automatically turned OFF to
prevent the possible swamping of other channels. To turn the
transmitter ON, use the RF_Out function.
RX_Freq Programs the demodulator receive frequency between 50 and 90 MHz,
or between 100 and 180 MHz, in 2.5 kHz steps.
On entry, the current receive frequency is displayed with the flashing
cursor on the first character. Use [
← ] and [ → ] to move the flashing
cursor. Use [ ↑ ] and [ ↓ ] to increment or decrement the digit at the
flashing cursor. Press [ENTER] to execute the change.
RF_Out Programs the modulator output to ON or OFF.
On entry, the current status of the output 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.
TX_Power Programs the modulator output power level from -5 to -30 dBm, in
0.5 dB steps.
On entry, the current transmitter power level is displayed with the
flashing cursor on the first character. Use [
↑ ] and [ ↓ ] to increase or
decrease the output power level, in 0.5 dBm steps. Press [ENTER] to
execute the change.
RFLoopBk
(Test Mode Configuration
Option)
Programs the modem for RF loopback operation.
When RF loopback is turned ON, the demodulator is programmed to
the same frequency as the modulator. When RF loopback is turned
OFF, the demodulator is tuned to its previous frequency.
On entry, the current status of the RF 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.
IFLoopBk
(Test Mode Configuration
Option)
Programs the modem for IF loopback operation.
When IF loopback is turned ON, the demodulator is connected to the
modulator output through an attenuator. The demodulator is
programmed to the same frequency as the modulator. An attenuator
within the modem connects the IF out to the IF in. When the IF
loopback is turned OFF, the demodulator is tuned to its previous
frequency, and is reconnected to the IF input.
On entry, the current status of the IF 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.