23
Figure 22
NMEA Outputs
The MiniPlex has two NMEA outputs called Out1 and Out2. Each output is capable of driving up to four
NMEA inputs.
The default communication speed of NMEA Out1 is set to 4800 Baud and NMEA Out2 is set to 38400
Baud. The speed can be set to any value from 4800 to 115200 Baud using MPX-Config.
Connect the A and B terminals of the NMEA output on the multiplexer to the A and B terminals of the
input(s) on the instrument(s). These terminals may also be labelled as Data+/Data-, RX+/RX-, In+/In–
or ve+/ve-.
Some instruments may have single ended inputs, with only one data terminal. Connect this terminal to
the A terminal of the multiplexer output, and leave the B terminal of the multiplexer output unconnected.
Connect the ground of the instrument to the Com terminal of the multiplexer output. Figure 23 shows
several examples of differential and single ended connections and combinations of both.
Warning
When using a single ended connection, the instruments data ground is often combined with its power
supply ground. In this case, it is very important to add an
extra wire between the Com terminal and
the Gnd terminal
of the multiplexer. If you fail to do this, the multiplexer may be damaged!
Figure 23
The shield terminals on the multiplexer (Shld) can be connected to the shield of the cable if available.
This should always be done on one end of the cable only, preferably on the end that is connected to an
NMEA output.
Multiplexer
In A
In B
Instrument
Out A/+
Out B/-
Differential
Multiplexer
In A
In B
Instrument
TX/Out
Ground
Single ended
Instrument
In A/+
In B/-
Multiplexer
Out A
Out B
Differential
Instrument
RX/In
Ground
Single ended
Com
Multiplexer
Out A
Out B
Com
Instrument
In A/+
In B/-
Multiple differential and
single ended listeners
Multiplexer
Out A
Out B
Com
Instrument
In A/+
In B/-
Instrument
RX/In
Ground
Gnd
