Furuno FR-1710 manual Setting a Target Alarm Zone, Measuring range and bearing Between two targets

3.Turn the VRM rotary control until the range marker on the No. 1 EBL aligns with target 2 in Figure 1-18. The active VRM readout at the lower-right corner of the screen indicates the distance between the two targets.

4.To return the EBL origin to the own ship position, press the [EBL OFFSET] key again.

You can repeat the same procedure on third and fourth targets by using the No.2 EBL and No.2 VRM.

Bearing is shown relative to own ship with suffix “R” or as a true bearing with suffix “T” depending on EBL relative/true settings on the OTHER menu.

	B
A	No. 1 EBL
	No. 1 VRM

	EBL		VRM
	80.0 R		0.50NM
Bearing from target A		Range between
to target B		target A and
		target B

Figure 1-18 Measuring range and bearing

between two targets

1.22 Setting a Target Alarm Zone

CAUTION

The target alarm feature should never be relied upon as the sole means for detecting the risk of potential collision. The operator of a ship is not relieved of the responsibility to keep lookout for avoiding collisions, whether or not the radar is in use.

The target alarm serves to alert the naviga- tor to targets (ships, landmasses, etc.) en- tering a certain area, with visual and audible alarms.

Note: The target alarm is given to targets having a certain level of echo strength. This level does not always imply a landmass, reef, ships or other surface objects but can mean returns from the sea surface or precipitation. Properly adjust the GAIN, A/C SEA, and A/C RAIN controls to reduce noise to avoid gen- eration of the guard alarm against false tar- gets.

The zone has a fixed width of 0.5 nm in the radial direction (depth) and is adjustable only within 3.0 to 6.0 nm from own ship. The outer and inner boundaries can be set at any dis- tance. The sector of the zone can be set any- where between 0 and 360 degrees in any direction.

To set target alarm zones:

1.Press the [MENU] key.

2.Press the [3] key twice to show the TGT ALARM menu.

		TGT ALARM
1.	AREA		NO1	NO2
2.	MODE1		IN	OUT
3.	MODE2		IN	OUT

Figure 1-19 TGT ALARM menu

2.Press the [1] key to select target alarm zone to use; NO1 or NO2.

3.Press the [ENTER/SELECT] key.

4.Press the [MENU] key.

5.Place the cursor (+) at point “A” (see fig- ure below) using the trackball. Press the [GZ ALARM] key. GZ1 (or GZ2) SET ap- pears. When both alarms are prepared the active alarm is circumscribed.

6.Move the cursor (+) to point “B” and press the [GZ ALARM] key again. Then, an echo watch zone as illustrated is created and the label IN (or OUT) replaces SET at the lower-right corner of the screen.

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