This form appears when you press
CHANGE UDP port in the parent Transmission
of Nmea 0183 Sentences form. You should enter the UDP port
number that the multiplexer uses.
UDP is a connection-less protocol. This means that the sender (the
PC in this case) just sends the messages and does not care if they
are received or not. In addition to specify the port number to
listen to, there is the need to specify the receiving IP Address,
i.e. the multiplexer IP Address.