Comtech EF Data SNM-1000 - Manual (Page 55)

SNM-1000 Node Control Modem Revision 3
Operation MN/SNM1000.IOM
3–13
3.4.1.3.2 INTERFACE:TX CLOCK PHASE
TX CLOCK PHASE
NORMAL
Programs the TX clock phase to AUTO, NORMAL, INVERT.
Upon entry, the current TX clock phase is displayed. Press [
↑ ] or [↓ ] to make the
selection. When AUTO is s elected, the modem will automatically select NORMAL or
INVERT to properly phase the TX clock with the TX data. Press to execute
the change.
3.4.1.3.3 INTERFACE:EXT-CLK FREQ
EXT-CLK FREQ
1544.000 KHZ
Programs the external reference clock input frequency between 8.0 kHz and 10.0 MHz.
Default: 1544 kHz.
Note: The clock rate must 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 external reference input.
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.