Furuno FA Manual page 155

Automatically acquired targets
The indication "TARGET-FULL(AUTO)" appears at the screen bottom and a
short beep sounds when the capacity for automatically acquired targets, as set
on the menu, is reached.
System failure alarm
When the SPU Board receives no signal input from the radar or external
equipment, the screen shows both "ARP SYSTEM ERROR" associated with an
indication denoting offending equipment, also releasing an audible alarm. The
missing signals are denoted as shown below.
Missing Signal
* Speed log signal
* Heading signal, Gyrocompass
Trigger signal from radar
Video from radar
* Bearing signal from radar antenna
* Heading pulses from radar antenna
* The alarm is available with or without ARP.
3. ARP OPERATION
Indication
LOG
GYRO
TRIGGER
VIDEO
AZIMUTH
HEADLINE
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