SeaTalk,
also known as SeaTalk1 to distinguish it from SeaTalkNG, is a
the proprietary "implementation of Nmea 0183" by Raymarine.
SeaTalk is a bus that carries marine data in a non standard serial
format. The segments of information that are transmitted
through the SeaTalk bus are called datagrams and, in most
cases, it is possible to convert those datagrams to
equivalent Nmea 0183 sentences. The Nmea4Wifi multiplexer
is capable of reading the SeaTalk datagrams and convert
them to Nmea 1083 sentences. The technical details of the
conversion can be found in the Vela-Navega Forum.
SeaTalk data is read on serial port P4. In order to tell
the multiplexer to interpret data arriving at P4 as
SeaTalk datagrams, we need to choose SEATALK, instead of
4800 or 9600, in the baud rate P4 combo box. The
SeaTalk bus has 3 wires that should be connected to the A4/B4 connector as shown in
the picture. It is possible to power the multiplexer from the
SeaTalk bus as shown with the dotted lines.