Furuno DS-30 ユーザーズマニュアル

 

 

3-11

When a TX trigger pulse (Keying Pulse) is connected from other acoustic equipment which 
gives interference to DS-30, note the following. 

1

2

3

4

5

6

TB3

External KP1

4mA

4mA

22

Ω

22

Ω

22

Ω

22

Ω

External KP2

 

1) Interference Rejection Signal Input Circuit 
Two iuput ports are provided in the processor unit for connection of KP for interference 
rejection. Use any one of them. 

2) Current Requirement 
Recommended current is 4 mA while the circuit operates normally at 2 mA to 20 mA. Adjust 
output resistance for the recommended current. 
 

The I/O circuit for NMEA or CIF format data has the configuration shown below, where CIF 
is Furuno standard data format. 
Maximum allowable current in NMEA output is 25 mA and recommended current is 10 mA. 
When terminating the line by a photo-coupler for a current loop configuration, take suitable 
means at the signal receiving side to limit the current. If, for example, forward voltage drop 
in the photo-coupler is 2.2V: 
 
[4.8 – 2.2 (V)]/[10(mA)] – 227 (

Ω) = 33 

(

Ω) 

 
therefore, 33 ohm resistor should be inserted in series in the line. 
 

The wind meter that outputs following dc voltages can be connected. 

-Wind direction: 

0 to 1 Vdc for direction of 0° to 540° 

-Wind speed: 

0 to 1 Vdc for speed of 0 to 60 m/sec 

 

The engine tachometer that outputs following dc voltage can be connected. 

0 to 1 Vdc for revolution speed of 0 to full scale.