Apols if any of this has been posted previously - I have just found
this newsgroup. It's pure dead brill.

Systems:-
Airmar DST 800 inputs to Actisense NDC4. Also coupled in to NDC4 is
Navman Wind and Garmin 182 GPS. USB from NDC4 to Tosh laptop running
Chart Navigator Pro.
Output to dsc radio from NDC4 ok

Issue 1
Chart Nav Pro shows DST info (well, everything it can as it is still on
land - hence no depth as yet). Wind info doesn't show up although CNP
shows data from AIS (separate usb port), GPS info and DST info. Logging
the port shows wind info being received however. Any ideas?

Issue 2
Fitted Navman repeater - can I take the output from either the NDC4 to
show all the info? (present limited attempt shows NMEA - "no" report on
Navman screen.

or

Can I wire the DST such that it feeds the NDC4 AND the Navman
repeater? If so how?

TIA
g

Mas Dubh :

Chart Nav Pro shows DST info (well, everything it can as it is still on
land - hence no depth as yet). Wind info doesn't show up although CNP
shows data from AIS (separate usb port), GPS info and DST info. Logging
the port shows wind info being received however. Any ideas?

Which wind sentences do you get? I have a similar problem with an old
anemometer whose wind sentences are not understood by the TackTick
repeaters. I use MaxSea on the computer to translate to newer nmea
sentences, and resend them to the TackTicks. If CNP cannot do that, it
should be fairly easy to program the translation.

Fitted Navman repeater - can I take the output from either the NDC4 to
show all the info? (present limited attempt shows NMEA - "no" report on
Navman screen.

Well, I have experience with the NDC4, but I don't know your navman
repeater. What kind of input does it require? RS232 or nmea? Which speed?
How did you connect it to the NDC4? I think the "ISO OUT 0" works at 38400
baud by default (it is meant to be coupled with "OPTO IN 0" to connect an
RS232 socket, to connect to a PC instead of the USB cable), so if your
repeater is a standard nmea device at 4800 baud, you should plug it on "ISO
OUT 1" (and check its speed with the )

BTW, I couldn't get the NDC4's filters to work, until I tried to connect it
to the PC with a serial cable instead of USB. This was pretty baffling. Do
you have the same issue?

On 2008-06-15 11:03:38 +0100, (Luc
Habert) said:

Mas Dubh :

Chart Nav Pro shows DST info (well, everything it can as it is still on
land - hence no depth as yet). Wind info doesn't show up although CNP
shows data from AIS (separate usb port), GPS info and DST info. Logging
the port shows wind info being received however. Any ideas?

Which wind sentences do you get? I have a similar problem with an old
anemometer whose wind sentences are not understood by the TackTick
repeaters. I use MaxSea on the computer to translate to newer nmea
sentences, and resend them to the TackTicks. If CNP cannot do that, it
should be fairly easy to program the translation.

Unfortunately the craft is some 70 miles away and I wont be over for a
week due to work (pah!) but I get your drift. I will check the
sentences next time. What is interesting is that CPN clocks it's an
"anenometer" that is fitted. Its data console however doesn't produce
the wind dir and speed (there are constraints in CPN on some consoles
if no SOG/COG is avail to calc apparent wind etc. which is
understandable) for say "Ground Wind". I'll look at the translation if
required althought this may be beyond my expertise just now.


Fitted Navman repeater - can I take the output from either the NDC4 to
show all the info? (present limited attempt shows NMEA - "no" report on
Navman screen.

Well, I have experience with the NDC4, but I don't know your navman
repeater. What kind of input does it require? RS232 or nmea? Which speed?
How did you connect it to the NDC4? I think the "ISO OUT 0" works at 38400
baud by default (it is meant to be coupled with "OPTO IN 0" to connect an
RS232 socket, to connect to a PC instead of the USB cable), so if your
repeater is a standard nmea device at 4800 baud, you should plug it on "ISO
OUT 1" (and check its speed with the )

Gosh - a host of stuff to check! Navman 3100 repeater can use navbus or
nmea inputs - I plumped for nmea in this case as I dont have a navbus.
Not sure about baudrate so, yes, there is a possibility that Navman is
missing the data if its firing in at 38.4k. I will check the NDC4
outlet too. I will also check that the 3 wires for nmea inputs are
similar - I only used the first one I came to.

Can one wire more than one pair of listeners to the "ISO OUT 1"?

BTW, I couldn't get the NDC4's filters to work, until I tried to connect it
to the PC with a serial cable instead of USB. This was pretty baffling. Do
you have the same issue?

YES! Is it not bizarre. I did get something on one nmea port once but
never manged to replicate. CNP seems to get some of what it needs
without it but it would help with all this buggering about to be able
to check what the NDC4 is hearing and speaking.
Plenty of food for thought and further research - many thanks.

Darkies Bum :

Its data console however doesn't produce the wind dir and speed (there are
constraints in CPN on some consoles if no SOG/COG is avail to calc
apparent wind etc. which is understandable) for say "Ground Wind".

Yes, it might be the cause too. Even though CPN should be able to display
the apparent wind without speed information, it may be that the programmers
were a bit lazy. There is a similar bug in MaxSea*: if MaxSea has not
received any GPS localisation sentence, it won't display the magnetic
heading from the compass... (I once lost an entire afternoon trying to
figure out why that new compass would not work...)

I'll look at the translation if required althought this may be beyond my
expertise just now.

I have a piece of code to multiplex and analyse the nmea sentences on the
PC, it should take only a few extra lines to make it perform this
translation, so let me know.

I will also check that the 3 wires for nmea inputs are similar - I only
used the first one I came to.

3 wires? Normally, there are 2 nmea wires per device. Is one of the data
wires shared with the ground?

Can one wire more than one pair of listeners to the "ISO OUT 1"?

Yes, the listeners are passive devices that just measure the difference of
potential between the two ports, so it's essentially like pluging voltmeters
in parallel. The NDC4 manual encourages doing it.

It's pluging several talkers on one listener that is dangerous*: there, the
output ports of the talkers, whose potentials vary independantly, are
connected by simple wires with a tiny resistance...

On 2008-06-15 19:49:36 +0100, (Luc
Habert) said:


3 wires? Normally, there are 2 nmea wires per device. Is one of the data
wires shared with the ground?

Sorry not clear enough the the Navman 3100 repeater has the
following wires:-
Red: +ve 12v
Black: -ve and common nmea
Orange and Blue: navbus + /- not used
White: nmea input 1 - (think I used this one as a logical step)
Yellow: nmea input 2
Green: nmea input 3

No mention in the bumpf of nmea (0183) speed! It can theoreticaly take
the sentences I am interested in repeating depth (DPT), speed (VHW),
current set (VDR) and a few others.
There is only the need for 2 listeners - at the moment. The primary one
is the DSC VHF which is fully functional and the secondary is the
Navman 3100 repeater which I should like to display as much of the info
the laptop is getting or producing.
In terms of listeners baudrate the Navman 7200 dsc vhf nmea is 4800 and
I assume (eek!) that the Navman 3100 repeater is the same.
I will clarify if it is critical which nmea input wire is used for
discriminating between sentences (maybe picky?) and required rate for
the 3100.

CNP has the facility to send out instructions to autohelms and the
sentences are nmea e.g. BOD, HDG etc.. so thats reassuring.

I should also like to send waypoint and routes to the Garmin via NDC4
(that may be a hassle switching from nmea to Garmin protocols) from the
Tosh or maybe to the 3100 repeater if it's more legible and simpler.

That's my wish list! Am I expecting too much?

The paralleling up of listeners is reassuring - I did read it in the
Actisense stuff now you mention it.

The great thing about this newsgroup stuff is your never alone and your
experience is very often never unique - especially farting about with
this sort of gear and not noticing it's going dark through the cabin
windows! Thanks for the offer of the code translator - I should like to
have a decko at it to see how it works. Take the pa out of my address
above if you wouldn't mind.

Mas Dubh :

Sorry not clear enough the the Navman 3100 repeater has the
following wires:-
Red: +ve 12v
Black: -ve and common nmea
Orange and Blue: navbus + /- not used
White: nmea input 1 - (think I used this one as a logical step)
Yellow: nmea input 2
Green: nmea input 3

Yuck! Sharing the ground on all inputs is a receipe for trouble. Nmea
devices are supposed to use differential signaling. I am not sure it is
necessary, but you may have to connect the B/- port of ISO OUT1 to the
ground, and, if you plug another device in parallel, make sure that it
either works in differential signaling (two input wires, separate from the
ground), or uses the same ground convention (and finally pray that you don't
fry the damned thing).

No mention in the bumpf of nmea (0183) speed!

Then it should be 4800, which is the speed defined in the standard.

I should also like to send waypoint and routes to the Garmin via NDC4
(that may be a hassle switching from nmea to Garmin protocols) from the
Tosh or maybe to the 3100 repeater if it's more legible and simpler.

You should check what kind of input your GPS expects. Ideally, it would just
be nmea at 4800 bps (with specialised sentences), in which case all you need
to do is connect the Garmin's input to ISO OUT 1. But it may be that it
expects RS232 at an exotic speed, in which case you would temporarily have
to connect it directly to your PC.