NMEA 0183 Expanders, Buffers and Amplifiers
NMEA 0183 Expanders, sometimes called Buffers or sometimes called Amplifiers, collect NMEA 0183 data, usually from a single listener input, and then repeat (send or talk) the data out multiple outputs (talkers).
Most NMEA 0183 expanders/buffers/amplifiers just duplicate the single string of data and then output (talk) it to other devices through 4, 8 or sometime additional outputs. Usually the expander will bring the output (talker) data to the NMEA 0183 electrical standard which is why some call them amplifiers. The Listener side of the multiplexer is opt-isolated from the talker side of the expander, but often times the outputs (talkers) side of the expander have a common ground between them. Some more advanced expanders have isolated grounds on the output side, providing better ground loop protection.