Ais Collision Alarm (Cpa, Tcpa); How To Set The Cpa And Tcpa Ranges - Furuno FAR-2228-BB Operator's Manual

4. AIS OPERATION
4.14

AIS Collision Alarm (CPA, TCPA)

This radar calculates CPA and TCPA by using own ship and relative target positions.
An AIS dangerous target is one whose CPA and TCPA are within the range of the CPA
and TCPA limits set in the TT/AIS box. The AIS symbol of an AIS dangerous target is
red and flashing, and is announced with the Alert "AIS DANGER OF COLLISION". Af-
ter the alert is acknowledged the target symbol is displayed in red color.
When a sleeping or an activated target violates the CPA/TCPA
alarm setting its symbol changes to the dangerous target
symbol (red and flashing) and the message "AIS DANGER OF
COLLISON" appears. Press the ALARM ACK key (or click the
[ALERT] box with the left button) to acknowledge the
CPA/TCPA alarm. The audible alarm is silenced and the
symbol stops flashing.
Take appropriate action to avoid collision.
4.14.1

How to set the CPA and TCPA ranges

CPA and TCPA ranges can be adjusted from the ap-
propriate indication in the [TT] box.
1. Left-click the [CPA/TCPA] indication to activate
the feature.
2. Place the cursor on the indication you wish to
adjust.
3. Left-click, or spin the scrollwheel, to adjust the settings as required. The settings
options are outlined in the table below.
Indication
CPA
TCPA
4-18
Dangerous target
Method
Left-click 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0 (NM)
Scrollwheel 0.1 to 20; 0 to 10 in 0.1 NM increments, 1 NM incre-
ments thereafter
Left-click 1, 2, 3, 4, 5, 6, 12, 15 (minutes)
Scrollwheel 1 to 60 minutes in 1-minute increments
Thicker than
activated target
TCPA setting
Left-click here to activate
CPA/TCPA settings.
Settings options
CPA setting