Message 
Class 
Description 
ALR
No. 
AIS Alarm 029 
Alarm 
no valid SOG information 
 
AIS Alarm 030 
Alarm 
no valid COG information 
 
AIS Alarm 032 
Alarm 
Heading lost/invalid 
 
AIS Alarm 035 
Alarm 
no valid ROT information 
 
AIS MAX Target  INFO  Maximum number of AIS targets.   
AIS PROC (Data)  Alarm  AIS processing circuit: No communication or communication error. 328 
CPA/TCPA  Alarm  There is a dangerous target.  301 
Lost  Alarm 
Failure in tracking the target that has been under tracking. 
Failure in receiving AIS target data for a specified time. 
 
New Target  Alarm 
Acquisition or activation of a target in the automatic acquisition / 
activation zone. 
302 
RADAR Alarm (In)  Alarm  Targets have entered the radar alarm range.   
RADAR Alarm (Out)  Alarm  Targets have left the radar alarm range.   
REF Target  Alarm  Decrease in the reference target accuracy.   
Trial  Warning There is a dangerous target, when trial maneuver is active.   
TT (Boot)  Alarm  Target tracking unit start failure.  344 
TT (Data)  Alarm  The target tracking unit is malfunctioning..  323 
TT 95% Capacity 
INFO 
Over 95% of the maximum number of targets to be tracked.   
TT MAX Target 
INFO 
The maximum number of targets is under acquisition.   
ALR No  : Unique alarm number in ALR sentence and ACK sentence. 
 
5-45