57
It is not an absolute measurement, but a number that represents the ratio of the
signal to some initial "good" value. The number is relative, but can indicate that the
model may be close to the range limit of the controlling aircraft.
When the return signal is completely lost, the remote control will prompt “Lost
return signal”. Please note that due to a failure of the return link, the remote control
can no longer warn you of RSSI or any other alarm conditions, so no further alarm
sounds.
Digital settings: