"Pascal" wrote in message
oups.com...
Thank You for the good idea, I have made a look in the AirCable site
and seems a good way to eliminate cables, but prior to use this, I
must have an AIS enabled Gps/plotter, which is what I am looking for
at the moment.

Regards

Pascal

2that come to mind
Raymarine C-series, Standard Horizon CP175-C .........
plano

plano wrote:
"Pascal" wrote in message
oups.com...
Thank You for the good idea, I have made a look in the AirCable site
and seems a good way to eliminate cables, but prior to use this, I
must have an AIS enabled Gps/plotter, which is what I am looking for
at the moment.

Regards

Pascal

2that come to mind
Raymarine C-series, Standard Horizon CP175-C .........
plano



I'm sure Pascal's glad you didn't mention Garmin ;-)

Ok, but as I have said, I want a "Portable" unit.. I know that there
are many models of gps/ploters that are AIS enabled, like those more
recent units from Garmin, Navman, Raymarine, etc but none of them are
"portable" (that is, battery operated and easily removable to be used
in another boat and at home).

Of course, the ideal for me would be a portable or handheld unit wicth
would be a combined "Gps-Plotter-AISReceiver" all in one, but in lack
of integrated AIS, the unit could be at last AIS Ready, using a
external AIS Receiver, preferentially, with integrated Bluetooth.

The classical "Nasa AIS Radar" was a very good idea, since in reality,
we really do not need a chartplotter, but it is not portable and not
weather proof to be used in the cockpit.

Thanks

Pascal

"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=

"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

"plano" wrote in
:

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




Listen to your VHF radio tuned to the two AIS channels. The traffic is
bursts of data with LOTS of dead time. At some point, you're right, it
could become saturated. But 4800 baud would handle the data I've heard
coming over the two channels very easily in busy Charleston harbor.

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

If averaged over 10 minutes or so, maybe 4800 would offer enough bandwidth
in certain locations, but you just cannot risk that say 20 (long) AIS
sentences are received more or less simultaneously. There is no way 4800
baud (1/8th!! of 38400) will handle that. Any idea how much traffic one
can expect say in the English Channel? It's the worst case scenario that
counts, not the average in Charleston harbor.
plano

"Larry" wrote in message
...
"plano" wrote in
:

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




Listen to your VHF radio tuned to the two AIS channels. The traffic is
bursts of data with LOTS of dead time. At some point, you're right, it
could become saturated. But 4800 baud would handle the data I've heard
coming over the two channels very easily in busy Charleston harbor.

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

"plano" wrote in
:

If averaged over 10 minutes or so, maybe 4800 would offer enough
bandwidth in certain locations, but you just cannot risk that say 20
(long) AIS sentences are received more or less simultaneously. There
is no way 4800 baud (1/8th!! of 38400) will handle that. Any idea
how much traffic one can expect say in the English Channel? It's the
worst case scenario that counts, not the average in Charleston harbor.
plano



You can watch the Irish Sea:
http://www.aisliverpool.org.uk/index.php
Finest AIS system on the internet.

But, of course, YOUR AIS isn't this good. Your range is about 10-12
miles with a 50' antenna listening to these 12W transmitters. This
limited range limits the number of AIS packets you must process in your
small system. That in itself reduces the load considerably.

Click on [Pan and Zoom] on the Liverpool AIS system. Zoom out until the
scale in the lower left bottom corner says 10 mi - 20 km on your screen.

Now, pan out of the Liverpool ship channel by the docks. Cruise the pan
out the channel into the Irish Sea, a busy place out from Liverpool. Go
off in the direction of the maximum density of ships you can find at the
time. Using the scale in the lower left hand corner as a RADIUS from
your boat, the actual range of your own AIS receiver in any at-sea
situation, how many ships can you get inside that 40 km circle around
your cursor? In Liverpool harbor, with a lot of ships docked but still
transmitting away on AIS, I can get, maybe 15 in range. Out at sea,
where we are concerned about this problem, the ships are spread out more.
If I center my boat 20 km N of Amtwch, the peninsula sticking out to the
East of Liverpool, at this moment I would be painting 7 or 8, tops.

Point is your boat-mounted AIS receiver's 20 km horizon ISN'T going to
paint all those ships you can see on this chart of Liverpool and the
Irish Sea, a very busy place for shipping. If 8 ships are transmitting
full AIS data into my system on 4800 baud every other second, it won't
tax the 4800 baud bandwidth anywhere near its limit to the point where it
would jam or nav data packets from the other instruments would be slowed
down to a crawl. It just won't happen, unless we put up a 1000' mast to
get more packets......

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

"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.....

You need to get your facts straight! A Raymarine C/E series chartplotter
runs at 38400 baud when in AIS mode. Most likely others do that too....

Oh and besides that, there is also something called NMEA0183-HS which IS
38400 at RS422.

Meindert

"Meindert Sprang" wrote in
:

You need to get your facts straight! A Raymarine C/E series
chartplotter
runs at 38400 baud when in AIS mode. Most likely others do that too....

Oh and besides that, there is also something called NMEA0183-HS which
IS
38400 at RS422.

Meindert



hMM....We're buying new equipment, again....sorry. What about wonderful
NMEA2000, or whatever NMEA is calling their latest and greatest version
to sell new equipment this month? Does it run 38,800 baud?

I'm still wondering why we don't just make the AIS receivers run 4800
baud. On a boat with a 12 mile range, there aren't enough AIS ships to
jam a 4800 baud port up, at least that couldn't be buffered cheaply for a
few milliseconds as it spits it out.

Do you know why they insist on 38,800 baud RS-232C, not RS-422 levels??
Seems really stupid to me.

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