Returning to my old subject, this weekend my friend had made the
software update for his C80 wich now is AIS Ready and we two now have
our respective SR161 AIS receivers working and running with the several
PC software (SeaClear, ShipPlotter, OziExplorer and SOB).

The problem which arises now is related to the availability of only one
NMEA port on the Raymarine C80 chart-plotter. I have not seen it (the
physical installation) but appears that this port already have one
connection that I think, it is the VHF/DSC connection, which is NMEA
IN for VHF and NMEA Out for C80.

The questions a

1) Supposing that the connection from the Gyro (which comes with the AP
Smart Pilot S1G) is made by Seatalk and not on the NMEA port, the NMEA
Out of C80 should be 4800 bps (GPS Out to VHF In) or must be 9600? I
heard anywhere some time ago that DSC mandates 9600... It is true?

2) Since the NMEA IN on the C80 (NMEA Out on the SR161) is 38400 bps,
this NMEA port on the C80 could work using NMEA IN at 38400 bps from
AIS and NMEA Out to VHF at 4800/9600 bps?

3) The boat has an AP Smart Pilot S1G, which is connected by Sea Talk
with the plotter C80. I do not know if the AP Gyro is connected
directly to C80 by NMEA. I hope that this is not our case. But, if this
would be our situation, it would be possible to disconnect the NMEA
link, so that this NMEA port would be free to connect the AIS receiver?


4)In this hypothesis, the output of the AP/Gyro would be routed
automatically via S1G to the C80/Radar /Plotter by SeaTalk? Could be
that this link is already working, since the AP is actually linked to
C80 by Seatalk?

On 2006-05-16 11:36:48 +1000, "Pascal" said:

Returning to my old subject, this weekend my friend had made the
software update for his C80 wich now is AIS Ready and we two now have
our respective SR161 AIS receivers working and running with the several
PC software (SeaClear, ShipPlotter, OziExplorer and SOB).

The problem which arises now is related to the availability of only one
NMEA port on the Raymarine C80 chart-plotter. I have not seen it (the
physical installation) but appears that this port already have one
connection that I think, it is the VHF/DSC connection, which is NMEA
IN for VHF and NMEA Out for C80.

The questions a

1) Supposing that the connection from the Gyro (which comes with the AP
Smart Pilot S1G) is made by Seatalk and not on the NMEA port, the NMEA
Out of C80 should be 4800 bps (GPS Out to VHF In) or must be 9600? I
heard anywhere some time ago that DSC mandates 9600... It is true?

The gyro is a board level option on the S1. If it came from the factory
as an S1G there is no external gyro. If it was added later it could be
external or it could be a board level upgrade. You will need to eyeball
it to see if this is so.


2) Since the NMEA IN on the C80 (NMEA Out on the SR161) is 38400 bps,
this NMEA port on the C80 could work using NMEA IN at 38400 bps from
AIS and NMEA Out to VHF at 4800/9600 bps?

AFAIK the baud rade is for both in and out. The C and E series do not
support split baud rates. I may be mistaken on this but I doubt it.


3) The boat has an AP Smart Pilot S1G, which is connected by Sea Talk
with the plotter C80. I do not know if the AP Gyro is connected
directly to C80 by NMEA. I hope that this is not our case. But, if this
would be our situation, it would be possible to disconnect the NMEA
link, so that this NMEA port would be free to connect the AIS receiver?

The AP has NMEA in/out so the current NMEA out to position info to the
VHF radio could be shifted to the AP thus freeing up the C80 NMEA port.



4)In this hypothesis, the output of the AP/Gyro would be routed
automatically via S1G to the C80/Radar /Plotter by SeaTalk? Could be
that this link is already working, since the AP is actually linked to
C80 by Seatalk?

Yes.

--
Regards,
John D Proctor

"Pascal" wrote in message
ups.com...
Returning to my old subject, this weekend my friend had made the
software update for his C80 wich now is AIS Ready and we two now have
our respective SR161 AIS receivers working and running with the several
PC software (SeaClear, ShipPlotter, OziExplorer and SOB).

The problem which arises now is related to the availability of only one
NMEA port on the Raymarine C80 chart-plotter. I have not seen it (the
physical installation) but appears that this port already have one
connection that I think, it is the VHF/DSC connection, which is NMEA
IN for VHF and NMEA Out for C80.

The questions a

1) Supposing that the connection from the Gyro (which comes with the AP
Smart Pilot S1G) is made by Seatalk and not on the NMEA port, the NMEA
Out of C80 should be 4800 bps (GPS Out to VHF In) or must be 9600? I
heard anywhere some time ago that DSC mandates 9600... It is true?

DSC is standard NMEA and therefore 4800 bps.

2) Since the NMEA IN on the C80 (NMEA Out on the SR161) is 38400 bps,
this NMEA port on the C80 could work using NMEA IN at 38400 bps from
AIS and NMEA Out to VHF at 4800/9600 bps?

Cannot be. The one and only NMEA port cannot send and receive at different
speeds.

I cannot answer the remaining questions. But Raymarine made this whole thing
very fuzzy. For instance, in the manual it says you can also set the NMEA
port to a "9600 Navtex" mode. Apparently people think that Navtext is also
NMEA and want to connect their gyro, AIS and a navtex receiver to a
multplexer, which will not work. If that NMEA port is set to Navtex, it will
not receive NMEA.

To overcome the speed problem, we have come up with a MiniPlex-AIS, which
has three inputs at 4800 and one input at 38400. The RS-232 port of this mux
goes to the C/E display, set to 38400. Data sent from the C/E display to the
multiplexer at 38400 is output at a separate NMEA port running at 4800. I
still have to test whether the NMEA port of the C/E displays can be
connected to an RS-232 port. Again, the manuals are fuzzy about this: The
terminals are called ve+ and ve-(common). Which leads me to believe that the
ve- terminals are connected together because both have "common" in their
designation. But this would be stupid because it violates the NMEA standard.
I spoke to a few people involved in the development of the C/E displays at
Raymarine and even they couldn't tell me clearly how the NMEA port is
setup....
So if someone out there with a C/E display could get his multimeter and
measure the resistance between both ve-(common) terminals, I would be very
interested in the result.

If on the other hand the NMEA interface is completely isolated from the rest
of the system, it will be no problem to connect it to an RS-232 port.

Meindert

"Pascal" wrote in message
ups.com...
Returning to my old subject, this weekend my friend had made the
software update for his C80 wich now is AIS Ready and we two now have
our respective SR161 AIS receivers working and running with the several
PC software (SeaClear, ShipPlotter, OziExplorer and SOB).

The problem which arises now is related to the availability of only one
NMEA port on the Raymarine C80 chart-plotter. I have not seen it (the
physical installation) but appears that this port already have one
connection that I think, it is the VHF/DSC connection, which is NMEA
IN for VHF and NMEA Out for C80.

The questions a

1) Supposing that the connection from the Gyro (which comes with the AP
Smart Pilot S1G) is made by Seatalk and not on the NMEA port, the NMEA
Out of C80 should be 4800 bps (GPS Out to VHF In) or must be 9600? I
heard anywhere some time ago that DSC mandates 9600... It is true?

2) Since the NMEA IN on the C80 (NMEA Out on the SR161) is 38400 bps,
this NMEA port on the C80 could work using NMEA IN at 38400 bps from
AIS and NMEA Out to VHF at 4800/9600 bps?

3) The boat has an AP Smart Pilot S1G, which is connected by Sea Talk
with the plotter C80. I do not know if the AP Gyro is connected
directly to C80 by NMEA. I hope that this is not our case. But, if this
would be our situation, it would be possible to disconnect the NMEA
link, so that this NMEA port would be free to connect the AIS receiver?


4)In this hypothesis, the output of the AP/Gyro would be routed
automatically via S1G to the C80/Radar /Plotter by SeaTalk? Could be
that this link is already working, since the AP is actually linked to
C80 by Seatalk?


Hi,
The Brookhouse NMEA multiplexer can combine four standard 4800BPS NMEA
talkers plus AIS at 38400.
Output to the C80 is RS422 (NMEA out) at 38400. In addition, RS232 is
standard available for computer connection, USB optional.
A user report can be found he
http://brookhouseonline.com/user_comments.htm

Wout

John Proctor wrote:
On 2006-05-16 11:36:48 +1000, "Pascal" said:

4)In this hypothesis, the output of the AP/Gyro would be routed
automatically via S1G to the C80/Radar /Plotter by SeaTalk? Could be
that this link is already working, since the AP is actually linked to
C80 by Seatalk?

Yes.


With the caveat that radar overlay and MARPA will perform worse. The
reason that Raymarine installs have heading information sent both by
seatalk and NMEA to their chartplotter/radar combinations is that the
heading is only sent once per second on seatalk, whereas it is sent 10
times per second over the NMEA port. This means that the heading can be
synchronized during the radar scan.

Whether this is noticeable in practice depends on your boat (how quickly
it yaws), and expectation level.

--
Kees

Ok but am installing an AIS which could overlay the targets on the
radar screen and calculates the CPA/TCPA; this turns the standard Marpa
function of the RADAR almost superfluous?

Thanks Meindert

Pascal

Pascal wrote:
Ok but am installing an AIS which could overlay the targets on the
radar screen and calculates the CPA/TCPA; this turns the standard Marpa
function of the RADAR almost superfluous?


As long as the other ships have AIS, yes.

Take a look at a picture I took on-board last year.

http://tinyurl.com/hpozz (small)
http://tinyurl.com/ebmda (full size)

Look carefully at the left part, which is chart overlayed with radar,
MARPA and AIS enabled. You'll see that the gray tail behind AIS target
A70 is much more straight than the green tail behind the MARPA target MR8.

Btw, yes the ship represented by A70/MR8 did almost hit MR7. They hadn't
seen each other apparently (this was in THICK fog on the middle of the
North Sea). MR7 did a pretty wild maneuver at about 200 yards from MR8.
Unfortunately I didn't take a screendump of that! I later asked the
skipper of MR8 whether he'd seen or heard anything. He said he had not,
and that he maintained careful radar watch: he checked the screen every
10 minutes but didn't see anything...

--
Kees

This seems to be very very cool, but the link you showed here is for
members of the Club only, and I can not access the photos . Can you
send the images to me by e-mail?

Thanks

Pascal

Kees Verruijt wrote:

Take a look at a picture I took on-board last year.

http://tinyurl.com/hpozz (small)
http://tinyurl.com/ebmda (full size)

Look carefully at the left part, which is chart overlayed with radar,
MARPA and AIS enabled. You'll see that the gray tail behind AIS target
A70 is much more straight than the green tail behind the MARPA target MR8.

Kees,

I think we need a link directly to the images, I seem to be getting to
an opening page but don't know where to find the photo. You might be
able to see things we are not because of cookies stored on your machine.

On some web pages, especially those using frames, I find it is sort of
difficult, if not impossible, to send a link to one of images or frames.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)