Comtech EF Data SDM-309B - Manual (Page 231)

External Channel Unit SDM-309B Satellite Modem
C-C–24 MN/U-SDM309B Rev. #
TX_Clock Programs the modem for internal or external transmitter clock.
On entry, the current status of the Transmit Clock is displayed with the
flashing cursor on the first character. Use the arrow keys to select
“Internal” or “External” transmit clock. Press the “Enter” key to execute
the change.
RX_Clock Programs the modem for inverted or normal receive clock.
On entry, the current status of the Receive Clock is displayed with the
flashing cursor on the first character. Use the arrow keys to select
“Inverted” or “Normal” receive clock. Press the “Enter” key to execute
the change.
Swp_Racq Programs the sweep reacquisition time from 0 to 999 seconds.
On entry, the current status of the sweep reacquisition is displayed with
the flashing cursor on the first character. Use the arrow keys to
increment or decrement the digit at the flashing cursor. Press the
“Enter” key to execute the change.
CW_Mode *Programs the modem for continuous wave mode.
Three modes of operation are available: center, dual, and offset
modes.
On entry, the “CENTER” mode is displayed. To activate this test mode
press the “ENTER” key. Use the arrow keys to select the “DUAL or the
“OFFSET” modes. To return to the “CONFIG” menu press the “CLEAR”
key.
Note: When the “CLEAR” key is pressed, the modem is configured to
the state it was in before “CWMode” was invoked and the transmitter is
automatically turned off to prevent the possible swamping of other
channels. To turn the transmitter on, use the “RF_OUT” function.
Center Mode:
Generates carrier at the current modulator frequency. This can be used
to measure the output power and output frequency.
Dual Mode:
Generates a dual side-band suppressed carrier signal. Side-bands are
at one half (1/2) the symbol rate from the carrier. This is used to check
the channel balance and carrier null.
Offset Mode:
Generates a single upper side-band suppressed carrier signal. The
upper side-band is at one quarter (1/4) the symbol rate from the carrier.
This is used to check the quadrature.
* Indicates Test Mode configuration option.