The NM42 multiplexer from NoLand Engineering combines up to four NMEA 0183 instruments into a common output.
Two output formats, RS-232 and RS-422, are provided. The output data rate is selectable at 4800 to 38400 baud.
The multiplexer reads and stores the incoming data from each instrument. Whenever a complete message is received,
the multiplexer automatically dumps it to the outputs while it continues reading the inputs. Therefore, complete
messages are dumped as soon as they are received without any loss of input data. A "Talker" port is also included
to allow a computer to request specific messages from instruments or to send data such as waypoints or steering
Installation of the multiplexer is simple. The module may be mounted to any convenient surface with all
connections made via a terminal strip. A 9 pin 'D' connector is provided for PC connection if desired. The unit
is fully automatic in that once power is applied, it immediately begins acquiring data without user interaction.
No software drivers are required and no software configuration is necessary.
An LED shows operating status of the multiplexer. Green indicates an input is receiving valid data. Red indicates
the talker port (TLK) is sending data. Yellow indicates an error has occured. Error messages are sent to the outputs
to aid in fault isolation.