Comtech EF Data SDM-9000 - Manual (Page 202)

Options SDM-9000 Satellite Modem
A–16 Rev. 4
A.2.4.1.1 DBS Mode TX SYNC Pulse Timing
In DBS mode, a one clock-period-wide sync pulse must be supplied coincident with the
first bit of the sync byte. However, it is not required that the MPEG-2 sync byte data
(0x47) be present, because the DBS sync-detect logic writes a new sync byte pattern
upon receiving the sync pulse.
After the sync byte interval, 187 bytes (1,496 bits) of packet data, followed by 16 bytes
(128 bits) of zeros, are supplied to the modem. Refer to Figure A-11.
Figure A-11. DBS Mode TX SYNC Pulse Timing
A.2.4.2 Timing for Receive Baseband Interface
A diagram of the timing for the receive baseband interface is shown in Figure A-12.
Figure A-12. Timing for Receive Baseband Interface