Comtech EF Data SDM-300L3 User Manual
Page 96
SDM-300L3 Satellite Modem
Revision 1
Front Panel Operation
MN/SDM300L3.IOM
4–28
FUNCTION SELECT: CONFIGURATION: INTERFACE:
TX CLOCK PHASE
TX CLOCK PHASE
AUTO
Programs the TX clock phase to AUTO, NORMAL, or INVERT.
Note: AUTO is the default.
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
FUNCTION SELECT: CONFIGURATION: INTERFACE:
EXT-CLK FREQ
EXT-CLK FREQ
1544.000 KHz
Programs the EXT REF clock input frequency between 8.000 kHz and 10000.000 kHz.
Notes:
1. When an ODU or BUC is operated with an EXT REF, 10 MHz is required.
2. The clock rate shall be equal to the data rate unless the asymmetrical loop timing
option is present.
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 64 kHz to 4.376 MHz. This can be used for the Doppler/
Plesiochronous buffer reference. It can be a reference to SCT. Use the master clock input
on J8 for the external master reference. The EXT REF on CP3 only allows for 1, 5, 10,
and 20 MHz EXT REF input.
Upon entry, the current setting for the EXT REF is displayed. Press [
←
] or [
→
] to
increment or decrement the digit at the flashing cursor. Press
change.