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Comtech EF Data SNM-1001L User Manual

Page 91

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SNM-1001L Satellite Modem

Revision 1

Front Panel Operation

MN/SNM1001L.IOM

4–27

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 to execute the change.

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 to execute the change.