3
rd
Generation Dual Channel
Compact RDMS
TM
Telemetry Receiver-Combiner
45
Quasonix, Inc.
Note that the AFC is automatically overridden (Off) if the demodulator can natively tolerate at least 50 kHz of
frequency offset. This prevents the AFC from potentially interfering with frequency tracking if AFC is unlikely to
be needed. Override may be disabled, and many other detailed AFC parameters may be controlled, via the command
line interface. Refer to the RDMS™ Access via Telnet and Serial Control Protocol Technical Guide for AFC
command details.
Figure 51: Advanced Settings Window, AFC Mode Menu
5.4.3.5.1 AFC Mode
– Track
When AFC Mode is set to Track, the AFC continuously attempts to estimate and compensate for the input frequency
offset unless the input Eb/N0 falls below a predefined threshold. This mode is best suited for dynamic frequency
offsets.
5.4.3.5.2 AFC Mode
– Hold
When AFC Mode is set to Hold, the AFC holds its current compensation. This mode is best suited for static
frequency offsets. It may be advantageous relative to the Acquire mode if the channel is initially “known good” but
may become impaired during a mission.
5.4.3.5.3 AFC Mode
– Off
When AFC Mode is set to Off, the AFC continuously provides zero compensation. This mode is best suited for
small frequency offsets that are within the amount of frequency offset that the demodulator can natively tolerate.
5.4.3.6
Best Channel Selector
The Best Channel Selector option sets the Best Channel Selector value to On or Off. When this option is checked
(On), the combiner data output selects the best channel (1, 2, or Combiner) based on DQM.