Followup to msg on Sun, 02 Mar 2008 06:11:56 -0600, Geoff Schultz
:
(Original msg on bottom)

Thanks Geoff,
you contribution is much appreciated. It's about what I was
forecasting to happen.
Cheers
Manlio



Manlio wrote in news:kgoks3lt7mrm6s0cavklpprrs2t1sf2kro@
4ax.com:

I have on board devices from Raymarine, working under SeaTalk protocol
and also a Raystar plotter using a NMEA GPS signal. On the boat there
is a NMEA to SeaTalk Bridge Unit, so exists a "mixing" of all the
data. Upto now : no problems !

My question:
I would like to add a second GPS (Raystar 125) connecting its SeaTalk
output signal to the SeaTalk network. This would be meant to be a
reserve in case of failure of the first one. May I leave it in
operation, having GPS data coming from two devices, or it's better to
keep it off and disconnected while the first one is in operation ?

In theory there should not exist collisions on the talker side, but
what about same data flowing on the same network ?

Appreciated your comments

Manlio

My experience with trying to solve the same issue was that it was better to
have one as a reserve (hot plug-in) instead of having them both active. I
had 1 NMEA which was connected to an NMEA input on the course computer and
1 SeaTalk GPS and there were issues that I can't really remember at this
point.

However, the solution that I finally came down to was unplugging the
SeaTalk GPS and having it as a stand-by unit. I seem to remember that it
had more to do with the fail-over not working well on the chartplotter (a
RayMarine C80 and a NorthStar 6100i (for hardware and software
redundancy)).

-- Geoff
www.GeoffSchultz.org