DESIGNER’S HANDBOOK 4189350049C EN
Page 87 of 206
5.8
NX1 and NX2 NMEA interface module
Serial NMEA data is often the primary data source for XDi-N. To receive
and transmit NMEA data the NX2 module must be mounted on the rear
plate of the XDi-N main unit.
To reduce the number of extension modules needed, NMEA data can be
shared with other XDi-N units via the CAN bus using the XDi-net
protocol. Basic numeric data can also be shared with XDi-D/M, but not
the special data formats like for example time/date and position). Other
devices on the CAN bus may also use NMEA data provided by the XDi-
N.
If only NMEA output data is required, the NX1 module can be used.
The NX1 NMEA output module contains one serial output following
IEC61162-1 (NMEA0183) and may be used to supply output data like
rudder angle and RPM to external devises like integrated navigation
system or a VDR.
5.8.1
Connection of the NX modules
Term. no.
Signal
NX2
Label
NX1
Label
Remark
1
COM 3 input
NMEA 0183
RX3
– B
Do not connect
Opto-insulated serial input
RS-422 (IEC 61162-1 and -2)
2
RX3
– A
“
3
COM 1 input
NMEA 0183
RX1
– B
“
Opto-insulated serial input
RS-422 (IEC 61162-1 and -2)
4
RX1
– A
“
5
Contact input 1 C-IN 1
C-IN 1
Push-button input 1 with internal
pull-up to +5 V
6
Contact input 2 C-IN 2
C-IN 2
Push-button input 2 with internal
pull-up to +5 V
7
COM 1 output
NMEA 0183
TX1
– A
TX1
– A
RS-422 Differential output
(IEC 61162-1)
8
TX1
– B
TX1
– B
9
Common GND COMMON
COMMON
Note1
10
COM 2 in/out
NMEA 0183
RX/TX2
– B
Do not connect
RS-485 configured as input or output.
11
RX/TX2
– A
Do not connect
Dill switch
(red)
RS-485
termination
See picture
above
No function
120 Ω termination resistor, default OFF.
The red dill switch is located above term. 10.
Note1: Common (Reference GND) for the RS-485 COM port, COM 1 output and the two contact inputs.
Important: The common GND terminal should NOT be connected to the NMEA cable shield, the cable shield
should be connected to a good ground connection in only one point !
NX2 is the extension module enabling the XDi-N to receive and transmit NMEA 0183 serial data (in accordance
with IEC61162-1 and -2).
When the NX2 module is mounted in the extension slot, several input/output ports are available for the serial NMEA
0183 data.
All serial inputs are setup to use the NMEA protocol and default port parameter setup in accordance with
IEC 61162-1.
By changing the bit rate from 4.8 to 38.4 kbps it complies instead with the NMEA high speed standard
IEC 61162-2.
XDi 96 N can have one NX2 module mounted on the rear plate.
XDi 144/192 N can have one or two NX2 NMEA modules mounted on the rear plate at the same time.
