"Steve Lusardi" wrote in message
...
Lisa,
NMEA interfaces are slow and bit serial (EIA RS-232). The protocol is very
basic and there is no provision for either addressing or data collisions.
As
you stated, your solution is incorrect, the device to use is called a
statmux or statistical multiplexor in general.

You don't need a multiplexer to feed one NMEA stream into more than one
device. You only need one when multiple NMEA streams, like from a GPS *and*
some nav instruments are to be fed into one listener, like a computer or an
autpilot.

The NMEA standard specifically states that one talker (a GPS) should be able
to drive up to four listeners *simultaneously*. So even according to the
official spec it is perfectly ok to connect the output of a GPS to the input
of a radar AND a VHF.

Meindert
www.shipmodul.com