"Quee Queg" wrote in message
...
Phil Stanton wrote:
First the good news

Cracked it

The so called NEMA output from a Raymarine Multi should be floating, but
the
positive terminal is at 12v; something to do with being able to use the
NMEA
out terminals for an alarm. This as it were "shorts out" the RS232 on
the
laptop

Now the bad news

You need a RayMarine PC/SeaTalk.NMEA Interface (E85001). Cost about
£100.
Yet another RayMarine Con, but it solved the problem

Phil


I don't get it, didn't you say earlier you already got a converter that
would convert the RS-422 NMEA output to RS-232?

That would still be a problem, since a real RS-422 input has two signal
lines that should be eachother's opposite in level. With the Raymarine
configuration this will not work. Only when the converter has an
opto-coupler input, as specified in the NMEA standard, it would have worked.

Meindert