For these who have the single output of NMEA data, please try below.

Connect the TX of your device to NMEA in- and then short connect GND with NMEA in + on A031. Make sure your NMEA 0183 device share the same power (normal the battery on your boat) with A031.

Below is an example show the wiring which AS06 connect to NMEA input1 of A031.

For some old devices, you probably need connect the TX to NMEA input +(not -) and the GND to NMEA input-, but this is uncommon.