3
rd
Generation Rack-
Mount RDMS™
140
Quasonix, Inc.
Modulation Index Scaling Mode contains four settings: Track, Hold, Off, and Acquire. Modulation Scaling is a
method used to retain the maximum trellis-coding gain of a non-ideal FM signal. For additional functional details,
refer to section 4.4.2.12 Modulation Scaling in the front panel section.
Figure 237: Advanced PCMFM Settings Window, Modulation Index Scaling Mode Menu
4.5.3.5.2 Modulation Persistence
Modulation Persistence allows the current state of the Modulation Scaling setting to be retained following a power-
off cycle. The default value is Off (not checked), as shown in Figure 238.
Figure 238: Advanced PCMFM Settings Window, Modulation Persistence Not Checked
When modulation scale index is set, the Modulation Scaling option on the Configure screen is simultaneously
changed to Hold. The Hold notation includes the new index number that the operator has chosen.
If the held index number is to be retained following a power-off cycle of the rack, then turn on Modulation
Persistence by checking the Modulation Persistence box on the Advanced PCMFM Settings screen. Save the current
setup profile using the Save Presets option. Refer to section 4.5.4.1.
When the RDMS™ is powered on, the default setting is Acquire, unless the unit
was powered off from a preset
condition. If the unit was powered off from an unmodified preset setting, then the default condition of Modulation
Scaling is as defined in the preset. When Tracking is set, the modulation scale index is actively being tracked.
Note:
The active setting is not saved when the rack is powered off, unless the Modulation Persistence option was set
to On.
