Furuno FM-8800D - Manual (Page 19)

1. OPERATIONAL OVERVIEW
1-7
1.1.4 Audio alarms
When you receive a distress alert or other DSC call, the audible and visual
alarms are released. For the distress or urgency call, the audio alarm sounds
until the CANCEL key is pressed. For all other calls, the audible alarm sounds
for two minutes and automatically goes off. The tone of the alarm changes with
the call received. By becoming accustomed to the tone, you can know which
type of call you have received.
Alarm Frequency (interval)
Safety call received
Routine call received
Message received from terrestrial
telephone line
Routine ack received
Safety ack received
750 Hz (50 ms) and 650 Hz (50 ms)
10 times,
Silence (2 S)
While DISTRESS key is pressed for four
seconds
2000 Hz (500 ms) silence (500 ms)
DISTRESS alert sent 2200 Hz continuous
Own ship position not updated 2000 Hz (250 ms) silence (500 ms)
DISTRESS alert received
DISTRESS Relay call received
2200 Hz (250 ms) 1300 Hz (250 ms)
Urgency call received 2200 Hz (250 ms) silence (250 ms)
DISTREES ack received
DISTREES Relay ack received
2200 Hz (500 ms) 1300 Hz (500 ms)
Urgency ack received 2200 Hz (500 ms) silence (500 ms)
When you call another handset terminal, or you are called by other handset
terminal, the following audible alarm is released.
Alarm Frequency (interval)
Intercomm alarm
800 Hz (50 ms) and 1000 Hz (50 ms)
3 times,
Silence (400 ms)
800 Hz (50 ms) and 1000 Hz (50 ms)
3 times,
Silence (2 S)