Actisense NDC-4, Install & User Manual

NMEA Data Multiplexer - NDC-4

Page 7

© 2015 Active Research Limited

1. Five Opto-isolated Inputs.

All inputs are of the differential opto-isolated type and use 

the unique 

Actisense

 low current drain circuitry (2mA @ 

2.0v) to conform in full with the NMEA 0183 marine 

electronic device network communication standard, and 

are flexible enough to interface to most fully and partially 

compliant devices.

2. Two ISO-Drive Outputs.

The ISO-Drive outputs comprise of two connections: ‘+/A’ 

and ‘-/B‘ and conform in full to the NMEA 0183 standard. 

3. RS232 Compatible Input/Output Option.

The ISO OUT 0 and OPTO IN 0 connections can be used 

as a bidirectional RS232 compatible port and is designed 

for direct connection to a Personal Computer (PC) or other 

marine device capable of interfacing to a standard RS232 

port. 

When a USB cable is powered and plugged into the NDC-

4, this port switches to output only - i.e. the RS232 input 

(OPTO IN 0) no longer operates.

4. A USB Input/Output (USB Variants Only).

The USB connector is designed for direct connection to a 

PC’s  USB  port.  Once  the  USB  cable  is  powered  and 

plugged into the NDC-4, Port 0 switches to an output only 

mode - this allows the USB port to take over bidirectional 

control of the NDC-4.

5. Battery Supply Input.

Standard battery power connections (8 to 35v).

Notes:

1.

 To complete the NMEA 0183 standard all device 

interconnection NMEA cables used should meet the two-

conductor, 

shielded, 

twisted 

pair 

configuration 

specification. The shield connection of these wires should 

be connected at the instrument end only to prevent ground 

loops.

2.

 Refer to 

“Specifications” on page 

19

 for the full details 

on input/output specifications.

The NMEA Data Multiplexer (NDC) has screw-terminal “Phoenix” type external connections for: -

Connections

Figure 1 – All external connections

NMEA DA

TA COMBINER 

99999 

NDC

-4-A-USB