User's Manual

AIS Class B Transceiver

being erased. However, if reception from the lost vessel’s AIS is re-

established, the icon will return to its previous state.

7.4 Collision Alarm – Guard Zone

This is a Level 2 alarm. The guard zone is determined by the radius

dimension entered by the user, as described in Section 5.5.1.2, and a red

circle will surround your vessel. The size of this circle will be dependent

on the display range selected.

Note If “Track Own Vessel” mode has been activated; the red circle will track

with your own vessel’s icon.

For every AIS equipped vessel entering your Guard Zone, an audible

alarm will sound, regardless of what screen the AI50 is in and a “Guard

Zone Collision Warning” window will be displayed. Fig. 7.3

To confirm and clear this alarm press the  MENU key. The icon of

the vessel which caused the alarm to activate will turn red, indicating an

alarm condition still exists.

Once a vessel leaves the Guard Zone its icon will return to the normal state.

7.5 BIIT Alarm

The BIIT (Built In Integrity Test) is a Level 2 alarm.

The AI50 is constantly monitoring and testing the integrity of the AIS

transceiver. Should a fault be detected within the unit, the small circle

situated in the bottom right hand corner of the display flashes red, and a

text message informs the user about the transceiver status.

The “BIIT” message will remain there until the fault is cleared by the

Fig. 7.3 – Guard Zone Warning