Futaba 8UHFS, 8UHPS - Manual (Page 20)

17
This warning appears when an [optional] CAMPac
memory module is used in the transmitter for the first
time. When the Plus (+)
DATA INPUT key is
pressed, initialization of the module begins, after
which the memory module can be used. Once the
module is initialized, the display will not appear
again.
Warning sound: A single beep This single beep lets you know that the RF module is
not installed in the transmitter.