Comtech EF Data SNM-1010L - Manual (Page 156)

SNM-1010L Data/Control Modem Revision 0
Clocking Options MN/SNM1010L.OM
5.1.5 Doppler Buffer Clock Source
The operator can select the Doppler Buffer Clock from the following sources.
• Continuous mode:
♦ Transmit Terrestrial Clock (must be within 100 PPM of nominal)
♦ Receive Satellite Clock (must be within 100 PPM of nominal)
♦ External Clock
♦ SCT, internal
• Burst mode operation does not support Doppler Buffer capability
5.1.5.1 Doppler Buffer Clock Source Specifications
Refer to the following listing for Doppler Buffer Clock Source specification.
Receive Clock Switching Due to
Failure of Selected Clock Upon failure of the selected clock, the modem automatically
switches the receive clock source to internal.
Receive Clock Phase Adjustment Operator-selectable to normal or inverted.
Receive Doppler Buffer
Operator-selectable to any capacity in the range of
64 through 65536 bit/s, in 16-bit steps (also selectable in
ms).
Buffer Centering
The operator sets the buffer to 50%.
After receive signal acquisition or a buffer
overflow/underflow, the modem automatically sets the
buffer to 50%.
Loopback Modes
Operator-selectable interface loopback test modes include:
• Baseband
• Near end
• Far end
5–6