Furuno 1734C, 1724C manual Lost Target, Setting CPA and Tcpa, Lost target, Confirming a lost target

5. AIS OPERATION

5.6Lost Target

A target is declared a lost target when no data is received for three to five reporting intervals. When this occurs, the target is marked with the (flashing) lost target symbol. However, the target which becomes a lost target is a activated target or a sleeping target within the lost target range.

Lost target

Confirming a lost target

1.Use the trackball to place the cursor where there is no ARPA target, marks or lines.

2.Push the ENTER knob.

5.7Setting CPA and TCPA

When the predicted CPA of any target becomes smaller than a preset CPA alarm range or its predicted TCPA less than a preset TCPA alarm limit, an audio alarm sounds, the messages CPA ALARM and TCPA ALARM appear, and the speaker icon appears (in red). In addition, the AIS target plot symbol of the offending target changes to a triangle and flashes together with its vector. You may silence the audio alarm with the CLEAR key. Press the ALARM key and the message “COLLISION ALARM” appears. Press the CLEAR soft key to acknowledge the alarm. The flashing of the triangle plot symbol continues until you intentionally terminate tracking of the target. The ARP continuously monitors the predicted range at the Closest Point of Approach (CPA) and predicted time to CPA (TCPA) of each track to own ship.

This feature helps alert you to targets which may be on a collision course with own ship. However, it is important that gain, A/C SEA, A/C RAIN and other radar controls are properly adjusted and the ARP is set up so that it can track targets effectively.

CPA/TCPA alarm ranges must be set up properly taking into consideration the size, tonnage, speed, turning performance and other characteristics of own ship.

Follow the steps shown below to set the CPA/TCPA alarm range:

1.Press the MENU key.

2.Press the SYSTEM CONFIGURATION soft key.

3.Press the GENERAL SETUP soft key.

4.Press the AIS OPTION soft key to show the AIS OPTION menu.

5.Choose CPA and then press the EDIT soft key to show the CPA window.

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