NorthStar Navigation NorthStar 491 Manuale Utente

To provide the best possible performance with the 491 echo 
sounder, Northstar recommends the use of an Airmar 

 

No echoes displayed on sounder screen.

Has the

navigatorʼs

Aux Port been

configured

for the

491?

Check

the 491's STAT

indicator

Is the 

Advance

Speed set to

zero?

YES

NO

YES

NO

OFF

STEADY

GREEN

Change the Advance Speed 
setting.

Configure the navigatorʼs
Aux Port for the 491. See 
Section 1 of this manual 
for instructions.

1. Check fuses and circuit 
    breakers.
2. Check power to 491 with 
    a voltmeter.
3. Verify that the data cable  
    between the navigator and 
    the 491 is properly wired 
    and connected.

491 is communicating with
 the navigator.
 
1.  Check transducer 
     connector for the 
     proper wiring.
2.  If wiring is correct,check 
     transducer impedance 
     with an ohmmeter.
3.  If the transducer is open 
     or shorted, replace it

There's a hardware problem
with the 491.

The 491 and the navigator
aren't communicating properly.
Check the wiring of the data
cable between the navigator
and the 491.

FLASHING
GREEN

RED