Comtech EF Data C5 - Manual (Page 144)

Operation C5/K1/K3 Integrated Satellite Terminal System
4–18 Rev. 0
4.1.3.3 Configuration Interface
Refer to Figure 4-6.
TX CLOCK SOURCE Programs the clock source for the modem transmitter clock to the
following configurations:
! TX TERRESTRIAL: Sets the TX clock to recover timing
from the incoming clock/data.
! SCT (INTERNAL): Sets the TX clock to operate from the
modem internal clock (this is also the fallback clock).
Note: When loop timing is enabled, SCT (LOOP) is
displayed instead of SCT (INTERNAL).
! EXT. CLOCK: Sets the TX clock to operate from the
external reference clock. Transmit Clock source must be
phase/frequency locked to the data that is being transmitted.
The correct frequency must be programmed into EXT-CLK
FREQ.
Upon entry, the current transmit clock setting is displayed. Press [
$]
or [
%] to make the selection. Press [ENTER] to execute the change.
TX CLOCK PHASE Programs the TX clock phase to AUTO, NORMAL, or INVERT.
Upon entry, the current setting of the TX clock phase is displayed.
Press [
$] or [%] to make the selection. When AUTO is selected, the
modem will automatically select NORMAL or INVERT to properly
phase the TX clock with the TX data. Press [ENTER] to execute the
change.
EXT-CLK FREQ Programs the external reference clock input frequency between
8 kHz to 10 MHz.
This clock frequency can be any multiple of 600 Hz from
2.4 to
& 64 kHz, and can be any multiple of 8 kHz from 32 kHz to
4.376 MHz. This can be used for the Doppler/plesiochronous buffer
reference. It can be a reference to SCT.
Upon entry, the current setting for the external reference is displayed.
Press [
"] or [#] to increment or decrement the digit at the flashing
cursor. Press [ENTER] to execute the change.