Furuno FS-1570 Service Manual page 193

6.5 TEST function in DSC SETUP menu
EXT ALARM
IC-303-DSC is tested. When [ENT] is pressed, the beep is released and the LED blinks on
IC-303-DSC. The same is done on FS-2570C.
To finish the test, press [CANCEL].
EXT ALERT
The distress alert transmitter is tested without actual transmission.
Select EXT ALERT and then press [ENT]. "Waiting for external alert sw." appears.
Press the distress alert button on IC-302-DSC, and the alarm is released and the LED blinks
on IC-302-DSC. After three seconds, the LED changed to on. The same is done on
FS-2570C.
To finish the test, press [CANCEL].
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