"Larry" wrote in message
...
"Pascal" wrote in news:1172160465.780416.309310
@q2g2000cwa.googlegroups.com:

I know that there
are many models of gps/ploters that are AIS enabled,

That all sounds good until you look at what comes out of the AIS at
38,800 baud RS-232 level data....then look at the GPS/Plotters plodding
along on RS-422 (NMEA-0183 isn't RS-232C compatible) at 4800 baud.....

Wrong baud rate, wrong voltage levels, INCOMPATIBLE AS USUAL....

"AIS Enabled" just means they'll read an AIS statement IF IT COMES IN AT
NMEA'S slow baud rate with the rest of the NMEA data. You can't just
plug them in, of course.

On Lionheart, our current configuration is an SR-161 receiver feeding a
Radio Shack RS-232C serial to USB interface cable ($10) plugged into a
USB port on the Dell Latitude notebook running the accompanying virtual
serial port software so The Cap'n nav software can find the 38,800 baud
data stream on what it thinks is a serial port. NMEA system data comes
in on another virtual serial port from my wireless router on the NMEA
system.

The Cap'n regurgitates the AIS data statements at 4800 baud to the NMEA
system so it will show up on any instruments capable of reading it.
SOME, not all, models of Raymarine and Garmin are capable of reading it
from the NMEA stream IF you upgrade their firmware or buy something new.
Currently, seeing the ships on the computer display chart is fine...(c;

I want to add another Webfoot RS-232C to Ethernet adapter to our Wireless
system. When I get that installed, I'm going to feed it the AIS data
from the SR-161 receiver. Being on a separate hard-wired Ethernet
address on our LAN, I'll be able to connect to its LAN IP address with
the second virtual serial port driver that comes with the Webfoot and can
eliminate the current Radio Shack hard-wired USB connection AIS is
attached to......making both NMEA at 4800 baud and AIS at 38,800 baud
available to The Cap'n WIRELESSLY so it will run anywhere on the
boat...or even at the yacht club bar if we dock the boat at the club...
(c;


NMEA out/in 1 4800 baud--Webfoot 1--Netgear wireless router port 1|
|
AIS SR-161-38.6Kbaud-----Webfoot 2--Netgear wireless router port 2|
|
RF-wifi radio link--------------|

RF-Wifi radio in laptop-|-Virtual serial COM2--The Cap'n NMEA in
|
|-Virtual serial COM3--The Cap'n AIS in



Larry
--
http://www.youtube.com/watch?v=fEJmc...elated&search=

I'm surprised the Cap'n can pass through (relay) AIS NMEA sentences, but
who is going to read them at 4800baud? All equiment that accept AIS do this
at 38400.
Also, if there is dense AIS traffic, you would soon run into bandwidth
problems running at 4800, the very reason why AIS uses 38400.
plano