Comtech EF Data SDM-9000 - Manual (Page 89)

SDM-9000 Satellite Modem Operation
Rev. 4 4–15
4.2.1.3 Configuration Interface
TX CLOCK PHASE Programs the TX clock phase to:
•
Normal
•
Invert
On entry, the current setting for the TX clock phase is displayed.
Press [
↑
] or [
↓
] to select Normal or Invert. Press [ENTER] to
execute the change.
Note: This menu is only available for the ECL, PECL, or
MIL-STD-188 interface.
EXT-REF FREQ Programs the external reference clock input frequency between
1544.000 and 51840.000 kHz, in steps of 8 kHz, or at data rate (if
data rate is over 20000.0 kbit/s).
On 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.
BUFFER CLOCK Programs the interface buffer output clock to one of the following
modes:
•
RX Satellite
•
Internal Clock
•
External Clock
•
TX Terrestrial
RX (Satellite) Mode:
Sets the buffer output clock to the satellite clock.
Internal Clock Mode:
Sets the buffer output clock to operate from the modem internal
clock. This is also the fallback clock.
External Clock Mode:
Sets the clock source to the external supplied buffer clock.
TX Terrestrial Mode:
Sets the buffer output clock to recover timing from the incoming TX
data clock.
On entry, the current setting of the buffer clock is displayed. Press
[
←
] or [
→
] to select Satellite, Internal, External Reference, or TX
Terrestrial for the buffer clock. Press [ENTER] to execute the
change.
Notes:
1. This menu is only available when the buffer is installed.
2. The buffer clock source selection must fall within the
parameters listed in Chapter 5.