beautypg.com

Comtech EF Data SNM-1001L User Manual

Page 216

background image

SNM-1001L Satellite Modem

Revision 1

Asymmetrical Loop Timing MN/SNM1001L.IOM

11–4

Example:

Master/Slave Clocking Setup:

1. Master site has a 10 MHz clock that is needed as the clock source.

2. Unequal data rates: 4.096 Mbps and 2.152 Mbps (numbers divisible by 8).


Master Site Option:

1. Set Configuration/Modulator/Modem Reference to EXT 10 MHz.

2. Set Configuration/Interface/TX Clock Source to SCT (Internal).

Note: The SCT clock is slaved off the 10 MHz input. The 10 MHz reference should be

placed into CP3 of the modem.

3. Set Configuration/Interface/Buffer Clock to SCT (Internal).

Slave Site:

1. Set Configuration/Interface/Loop Timing to ON.

2. Set Configuration/Interface/TX Clock Source to SCT (LOOP).
Or TX Terrestrial, Only if the user equipment can provide the proper slaved clock to the

modem.


3. Set Configuration/Interface/Buffer Clock to RX Satellite (Buffer Bypass).