Operator's Manual

6. RADAR
6-33
6.27.6 CPA/TCPA Alarm
The CPA/TCPA alarm helps warn of possible collision conditions. The ARPA continu-
ously monitors the predicted range at the Closest Point of Approach (CPA) and pre-
dicted time to CPA (TCPA) of each tracked target. When the predicted CPA or TCPA
is less than their set values, the buzzer sounds and a text message appears. The
ARPA symbol changes to a (red) triangle.
This alarm helps you keep your vessel away from collision by warning of targets on a
collision course. Make sure that the gain, sea and rain controls are correctly adjusted
before you use this alarm.
CPA/TCPA alarm ranges must be set correctly according to the size, tonnage, speed,
turning performance and other characteristics of your vessel.
How to set the CPA/TCPA Alarm
1. Press the MENU key to open the menu.
2. Open the [Alarm-Target] menu, shown right.
3. Use the RotoKey to select [CPA/TCPA
Alarm] then push the key to activate the
alarm on (status icon in green).
4. Use the RotoKey to set CPA and TPCA val-
ues at [CPA Alarm Value] and [TCPA Alarm
Value].
5. Press the MENU key to close the menu.
How to acknowledge the CPA/TCPA Alarm
The CPA/TCPA alarm sounds when the CPA and
TCPA of an ARPA target are within the CPA/
TCPA alarm range. To acknowledge the alarm
and stop the audio alarm, press the CANCEL key. (The ARPA vector must be dis-
played at least 30 seconds to calculate CPA and TCPA.)
How to deactivate the CPA/TCPA Alarm
Show the status icon of CPA/TCPA Alarm in the [Alarm-Target] menu in gray to deac-
tivate the CPA/TCPA alarm.