Onwa Marine Electronics KR-1338C v.2 - Manual (Page 9)

AIS Collision Alarm (CPA, TCPA)
The AIS continuously monitors the predicted range at the Closest Point of
Approach (CPA) and predicted time to CPA (TCPA) of each AIS target. When
the predicted CPA of an AIS target becomes smaller than a preset CPA range
and its predicted TCPA less than a preset TCPA limit, the audio alarm sounds
and the symbol of the offending AIS target becomes red, bold 2 times and
flashes together with its vector.
CPA/TCPA alarm ranges must be set up properly taking into consideration
the size, tonnage, speed, turning performance and other characteristics of
own ship.
Setting the CPA and TCPA ranges
Enter AIS menu, select 6. CPA. Set & 7. TCPA. Set , then press direction
key choose the value you want.
Below are CPA & TCPA can be setup value
CPA. Set Off, 0.5, 1, 2, 3, 5, 6 nm
TCPA. Set 30 s, 1, 2, 3, 4, 5, 6, 12 min
AIS symbol size setup
AIS symbols default has three different sizes, which can be according to
actual condition, and can also be set to automatic. When set to automatic
the size of AIS symbol will automatically change the range.
Setting the AIS symbol size
To set the AIS symbol size, enter AIS menu, select 8. Target Size and
press direction key choose L(long), M(medium), S(small) or AUTO, then
press [ACQ/ENTER] key to confirm.
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