On Jul 19, 10:38*am, Josh Assing wrote:
The SR161 can be used to consolidate incoming NMEA positional data from a
GPS with the AIS NMEA data into a combined high-speed data stream on a
single serial port.

In that scenario there is no need for any multiplexer.

but how does it talk to other non-high speed nmea devices then?

Basically you can take any inbound NMEA data stream or combined
datastreams at 4800 and the SR161 will combine that data with the AIS
data and output the combine original and AIS data streams on a single
outbound port. It is only for inbound data. You can't have two way
communication to the original NMEA devices - just an inbound feed to
the AIS receiver from the NMEA data stream.