Simrad RS20S User Manual page 17

Receive distress while off
Enabling this feature will allow the radio to raise an alert for DSC
distress calls, even when the DSC feature is turned off. This will work
regardless of whether or not an MMSI number has been entered.
DSC timeout
An inactivity timeout can be set up to return the radio to normal
operational mode when no activity is seen from the radio operator
while radio is engaged in a DSC call.
Distress calls have a discrete timer from that used for all other DSC
calls:
Distress
Select between NONE, 5 MINS, 10 MINS and 15 MINS.
(default is NO TIMEOUT).
Non Distress
Select between NONE, 5 MINS, 10 MINS and 15 MINS.
(default is 15 MINS).
Alarms
GPS alert
The GPS alert is a warning to the user that the selected GPS source
is not outputting valid position data.
It comprises of an audible alarm and visual alarm (screen flash and
warning text).
GPS alert function
Turns ON or OFF all alerts for missing GPS data, including audible
alarm, screen flash, and warning text.
Alert volume
Select between HIGH, LOW, and OFF.
Screen flash
Select between ON and OFF.
WX alert (US/CAN only)
The WX alert is a warning to the user that a special weather station
alert has been received.
It comprises of an audible alarm and visual alarm;
The radio menus | RS20S User Guide