Furuno 520 Operator's Manual page 34

3. STEERING MODES
Button (FAP-6211, 6212), Lever (FAP-6221, FAP-6222),
Dodge (FAP-6231, 6232) type remote controller
These controllers may be used in the STBY, AUTO and NAV modes.
1. For button and lever type remote controllers, turn on the remote controller
power.
The dodge type remote controller doesn't have the power switch, it can be
operated by simply pressing the direction buttons.
The indication "NFU" (No Follow-Up) appears on the control unit. (For dodge
type, NFU appears while a direction key on it is pressed.)
Course set
Non-Follow up (NFU) is a manual steering mode that moves the rudder as long
as the button or lever is pressed.
3-18
Turning power on, button and lever type remote controllers
FU mode
(Non Follow-up)
NFU
359
RUDDER
20 10
40
Rudder angle (XTE or Deviation)
NFU (No Follow-Up) mode display
Heading mode
M: Magnetic
T: True
HDG
359.9
M
0
40
10 20
Heading from
heading sensor