Comtech EF Data SDM-300A - Manual (Page 311)

SDM-300A Satellite Modem Revision 6
Asymmetrical Loop Timing MN/SDM300A.IOM
12–5
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).