Here is my current situation (Not resolved)

I have the following equipment which may be relevant. Raymarine S2G course computer controlled by a ST6001, ST60 Tridata, ST60 Wind and ST60 Multi.

I want to get NMEA data (Wind & Depth) into the 9 pin serial port on my laptop. For investigative purposes I am using Windows XP home edition and HyperTerminal to look at what is coming in, although I use Chartwork's Winchart NautiQ for navigation.



If the laptop is not connected to anything at all (including power supplies) I get valid NMEA messages from the NMEA Out from the Multi. If I connect the laptop to the boats 12v supply via a cigarette type laptop power supply, or an inverter using the normal laptop power lead I get nothing.


Equally if I connect the USB port via a Serial to USB lead to the GPS and AIS input I immediately loose the NMEA input.


If, with the computer isolated and the NEMA going in correctly via the serial port I connect the optocoupler input across the NEMA out terminals I again loose the signal. It is as if there isn't enough power in the NEMA signal to power anything.

I have replicated everything on my son's laptop, a totally different make so I think we can eliminate the computers. I can connect the laptop through a cigarette type laptop power supply to an external car battery and again no problem.

If I connect the negative of this spare battery to the negative of the ship's battery I immediately loose the signal.


2 other things. If I put a GPS signal into the serial port there are no problems even when the laptop is connected to the ship's power supply again confirming that the laptops seem OK and that HyperTerminal is configured correctly.



Here are various voltages that may give you some clues. Obviously measures with an electronic multi meter as I do not have a 'scope. Negative of meter connected to Negative of boat

NMEA output from Multi with nothing connected to it.

NMEA Out Negative to Ships Negative Fluctuating between -0.3 & 0.0v

NMEA Out Positive to Ships Negative 11.7v

NMEA Out Positive to NMEA Out Negative Fluctuating between 5.5 & 0v (Normal NMEA output)



Laptop connected to ships 12v supply though car type power supply. Nothing else connected.

Voltages on RS232 9 pin plug

Pin 5 to Ships Negative 0.18v

Pin 2 to Ships Negative 0.24v

Pin 2 to Pin 5 .05v



NMEA Out plugged into Laptop Serial Port, laptop on internal batteries. No other connections to laptop

NMEA Out Negative to Ships Negative Fluctuating between 8.8 & 4.7

NMEA Out Positive to Ships Negative 11.9v

NMEA Out Positive to NMEA Out Negative Fluctuating between 3.3 & 0v (NMEA received correctly)



NMEA Out plugged into Laptop Serial Port. Laptop connected to ships 12v supply though car type power supply

NMEA Out Negative to Ships Negative 0.2v

NMEA Out Positive to Ships Negative 11.6v

NMEA Out Positive to NMEA Out Negative 11.4v (No NMEA input detected)





NMEA From GPS plugged into Laptop Serial Port, laptop connected to ships 12v supply though car type power supply

NMEA Out Negative to Ships Negative 0.2v

NMEA Out Positive to Ships Negative Fluctuating between -3.0 & +0.2

NMEA Out Positive to NMEA Out Negative Fluctuating between -3.3 & +0.8 (GPS messages received correctly)



So there we are, getting NMEA out, but not in



Phil





"Arnold" wrote in message ups.com...
hey people,

a milestone for me, and possible, others:
raytheon answerd my mail, and said that an other instrument with native
NMEA support does recognise the sentences/data properly and that I
should try to connect the PC through that device. so the solution would
be, link a NMEA repeater to the NMEA OUT port and link the PC to that
thing.

as I just figured out, my Navtex receiver (furuno Nx-300) will, most
likely, do just that, with a semi-official rs-232 connection to it.
(semi, couse you have to put your own rs-232 plug on to the correct
wires).
I'm gonna keep you guys informed on later developments.

greetings,
Arnold

hey Phil,

the data you gave me is valueble, but I am missing one very important
thing (what the problem might be). what is the voltage of your
powersupply? (test by voltage meter, and the reading of the St60
multi), if that lies arround the 11 volts (or 11.9 as in the data you
wrote), it might be to low, and the batteries sort of dead. A 12V
powersupply should be somewhere arround 13.x V when charged. I have 4x
105ah 12v battieries installed, and when my voltage drops below 12.5
volt, I desperatley need charging.

if this is the case, try linking the instruments on a other battery
(just for the test, don't make it expensive, use a spare one or
something), and hook up your laptop to that thing too. If my thoughts
are correct, this should work.

(a lack of power supply affects your data, so when an other device is
linked, the voltage drops a bit further and the data is crippled/not
send) an other problem could be te capasity of the powersupply, if this
is to little, the voltage drops even further.

as for my own problem, it is still at the same point, wich is:
"theoreticly solved". I'll need to find time, somewhere in the next 1.5
week.

succes to you,
Arnold

PS:
where are you from?, I am from the netherlands.

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


"Arnold" wrote in message
oups.com...
hey Phil,

the data you gave me is valueble, but I am missing one very important
thing (what the problem might be). what is the voltage of your
powersupply? (test by voltage meter, and the reading of the St60
multi), if that lies arround the 11 volts (or 11.9 as in the data you
wrote), it might be to low, and the batteries sort of dead. A 12V
powersupply should be somewhere arround 13.x V when charged. I have 4x
105ah 12v battieries installed, and when my voltage drops below 12.5
volt, I desperatley need charging.

if this is the case, try linking the instruments on a other battery
(just for the test, don't make it expensive, use a spare one or
something), and hook up your laptop to that thing too. If my thoughts
are correct, this should work.

(a lack of power supply affects your data, so when an other device is
linked, the voltage drops a bit further and the data is crippled/not
send) an other problem could be te capasity of the powersupply, if this
is to little, the voltage drops even further.

as for my own problem, it is still at the same point, wich is:
"theoreticly solved". I'll need to find time, somewhere in the next 1.5
week.

succes to you,
Arnold

PS:
where are you from?, I am from the netherlands.

hmm, you bought the thing already?

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?

-- Kees

"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

Tried the OptoCoupler route, but that didn't work



I was under the misapprehension that when the RayMarine ST60 Multi has 2
pairs of terminals marked MNEA In and NMEA Out, that's what you got.
Yes I got so frustrated that I bought their interface as it was costing me a
fortune in time trying to get some sense. The technical department at
Raymarine didn't come up with the solution although it must be pretty common
problem.

Mind the are not very helpful when it comes to their echo sounders either. I
have a lifting keel boat and want to set the offset so that the echo sounder
reads zero with the keel down and just scraping the bottom. Trouble is when
I half lift the keel and go into shallower water I want the echo sounder to
show a negative amount. Of course it just continues to show zero. Yes - I
know I can set it below water line etc, but it's nice to know if the echo
sounder says 1.5m that is actually the "spare" water kicking around under
you, and you don't have to do a calculation. Most of the boats I sail on are
calibrated this way, so its what you see is what you get none of this
business that on John's boat you deduct 1.4 from the depth shown, whilst on
Pets boat deduct 1.8. (We English East Coast sailors are grateful to have
0.3m under us)


"Meindert Sprang" wrote in message
...
"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