This read-write object sets the Eb/No alarm threshold in 0.1 dB units, valid between 0.1 dB and 16 dB. This threshold determines at what signal quality margin the unit raises an alarm, surfaced via cdd564RxAlarm's ebNoAlarm(13) state, so setting it too close to the link's typical operating Eb/No causes nuisance alarms during normal signal variation, while setting it too low means real degradation could go unnoticed before an outage. For a link that normally operates around 8 dB Eb/No with a few dB of rain-fade margin, an admin might set this alarm point to roughly 5.0 dB so an alert fires well before the link is at real risk of losing lock during a fade event.