Rack-Mount RDMS
TM
Telemetry Receiver
86
Quasonix, Inc.
Mod Scaling should be turned off when a new generation, digitally synthesized transmitter is the source. Digitally
synthesized transmitters do not have a variable deviation sensitivity adjustment, and as such are not subject to
inaccurate modulation index settings
When Modulation Scaling is set to Acquire, the graphs display in yellow, as shown in Figure 153.
Figure 153: Modulation Scaling Set to Acquire, Signal Graph Displays Yellow
Acquire mode has two states: Armed and Triggered. When Modulation Scaling is set to Acquire, the state is set to
Armed. In Armed state, modulation scaling operates continuously.
If the receiver is locked and the delta h (the change in modulation index) has settled below the delta h threshold for
the specified settling time, the state changes to Triggered and the eye pattern turns green. In Triggered mode, the
estimated h (modulation index) is monitored but the scale is not updated.
If delta h goes above the delta h threshold and settles again, the receiver is still locked, and the Eb/N0 at the settling
point is higher than the last settling point, the current scaling is updated with the new estimate.
There is no transition from Triggered back to Armed except for setting the mode to Acquire again.