FUTABA 12K Instruction Manual page 104

TELEMETRY : Rx-BATT.
In this screen, the battery voltage of a receiver is
displayed.
If it becomes higher or lower than the setting an
alarm and/or vibration will alert you.
RTN
HOME/EXIT
RETURN
Alert set
*When the RTN button is pushed for one second, the rate is
reset to the initial value.
<Functions of Linkage Menu>
104
*It cannot be used in S-FHSS mode
<Push Dial>
"Vibes" type
If the following types are selected, the transmitter will
vibrate during the warning.
TYPE 1
TYPE 2
TYPE 3
TYPE 4