Figure D-5. Continuous And Gap Clock At Tt - Comtech EF Data CDM-710 Installation And Operation Manual

CDM-710/L Broadcast Satellite Modem
Appendix C
Clock / Data Relationship
The data transitions occur during the OFF to ON transition of the clock. Data is
stable during the ON to Off transition of the clock.
Tx / Rx Clock
Asymmetrical clocking with Rx Doppler buffer disabled.
Tx Clock Modes
• TT (Input clock) continuous.
• ST (output clock) is continuous output, programmable in 1 bps steps or
phase locked to satellite clock.
Rx Clock Modes
RT (output clock) is continuous from satellite, ST (internal clock), TT.
Gap Clock
Not allowed – Send ST to external equipment so that it returns a continuous
clock. See Figure D-5.
Continuous Clock
Gap Clock

Figure D-5. Continuous and Gap Clock at TT

TA / CA
• Default: CA looped to TA.
• Selection: CA is asserted when there is no modem fault.
Acquisition Range
Programmed Tx data rate ±100 ppm.
Test
• I/O Loopback per Chapter 7. FRONT PANEL OPERATION.
• Interface Loopback per Chapter 7. FRONT PANEL OPERATION.
C–7
MN/CDM710.IOM
Revision 12