3
Connections
NMEA Listener Ports
The MiniPlex-41USB has four listener ports, ‘In 1’ to ‘In 4’. Each listener port should be connected
to one instrument only. These inputs are galvanically isolated from the multiplexer, as specified in
the NMEA-0183 standard.
Connect the ‘a’ and ‘b’ terminals of the listener port on the MiniPlex-41USB to the ‘a’ and ‘b’
terminals of the talker port on the instrument. Other designations used are ‘Data +’ and ‘Data -’,
‘TX+’ and ‘TX-’ or ‘Out +’ and ‘Out –’.
Some instruments have single ended talker ports, with only one data terminal. Connect this
terminal to the ‘a’ terminal on the MiniPlex-41USB, and connect the ‘b’ terminal on the MiniPlex-
41USB with the instrument ground.
Instrument
Multiplexer
Instrument
Multiplexer
TX
GND
Differential
Single-ended
Out A / +
Out B / -
In A
In B
In A
In B
NMEA Talker Ports
Both talker ports can be connected to up to four instruments. Connect the ‘a’ and ‘b’ terminals of
the talker port on the MiniPlex-41USB to the ‘a’ and ‘b’ terminals of the listener port(s) on the
instrument(s). Other designations used are ‘Data +’ and ‘Data -’, ‘RX+’ and ‘RX-’ or
‘In +’ and ‘In –’.
Some instruments have single ended listener ports, with only one data terminal. Connect this
terminal to the ‘a’ terminal on the MiniPlex-41USB, and leave the ‘b’ terminal on the MiniPlex-
41USB unconnected. Connect the ‘Com’ terminal on the MiniPlex-41USB with the instrument
ground.
Multiplexer
Instrument
Multiplexer
Instrument
Differential
Single-ended
RX
GND
Out A
Out B
Out A
Out B
In A / +
In B / -
GND
GND
Multiplexer
Out A
Out B
GND
Instrument
In A / +
In B / -
Instrument
RX
GND
Instrument
In A / +
In B / -
Multiple instruments
