Raymarine DSM300 - Manual (Page 29)

Chapter 3: System Setup 29
When the Soft Keys option is set to OFF, the default soft keys are only displayed
when a soft key is pressed and they disappear if no operation is performed for 10
seconds.
Key Beep
This option controls whether or not the keys sound a tone when you press them.
MOB Data
This option controls whether MOB data is based on position data, or on dead
reckoning (DR). Dead reckoning normally provides a better indication of the
course to an object in the water, on the assumption that your boat and the object
are both subject to the same tide and wind effects.
Autopilot Pop Up
This option controls whether or not the autopilot pop up is displayed. When set to
ON, when the status and locked heading of the autopilot changes, they are
displayed in a pop up box. The box is removed from the display after two seconds.
When Autopilot Pop set to OFF, the pop up box is disabled.
Menu Timeout Period
With no timeout set, menus and soft key labels remain displayed until you clear
them by pressing ENTER, CLEAR or the appropriate dedicated key.
If you set a value here, the menus and soft key labels are cleared if a key has not
been pressed for the specified number of seconds.
This setting does not affect the default soft key labels, which are controlled by the
Soft Keys option (see above).
Units
You can set the units for speed, depth, and temperature. The units you set will be
used to display all data, including information received from other instruments on
the system. However, the distance units do not affect the instrumented range of
the radar, which is always in nautical miles.
Note: The ‘Units’ values set here are also used in the other display modes.