Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated

Gaby

"Gabriel Latrémouille" wrote in message
. cable.rogers.com...
Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated

You can do that with our multiplexers. You can connect up to four
instruments (outputs) to four inputs on the multiplexer. The RS-232 or USB
output from the multiplexer feeds the combined NMEA data to your computer.
At the same time, the combined NMEA data is available on two NMEA outputs on
the multiplexer, one of which can be connected to your radar.

Meindert
www.shipmodul.com

hello

there a company called marine electronic supplies (MES) and i think
there in southampton, but i moght be wrong. they do a box called an nema
splitter, feed a gps in and you can get anywhere from 2 to lots and lots
of outputs, think they start around £200,

regards

Meindert Sprang wrote:
"Gabriel Latrémouille" wrote in message
. cable.rogers.com...

Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated


You can do that with our multiplexers. You can connect up to four
instruments (outputs) to four inputs on the multiplexer. The RS-232 or USB
output from the multiplexer feeds the combined NMEA data to your computer.
At the same time, the combined NMEA data is available on two NMEA outputs on
the multiplexer, one of which can be connected to your radar.

Meindert
www.shipmodul.com

"Birdog" wrote in message
...
hello

there a company called marine electronic supplies (MES) and i think
there in southampton, but i moght be wrong. they do a box called an nema
splitter, feed a gps in and you can get anywhere from 2 to lots and lots
of outputs, think they start around £200,

But you cannot use a splitter to combine the outputs of different
instruments together to one. That can only be achived by a multiplexer.

Meindert

We're using a 4-port Noland multiplexer made to go with The Cap'n nav
software aboard Lionheart. The four talkers in the network a

Raymarine RL70CRC color radar/chartplotter with Seatalk Smart Heading
Sensor (gyro-compass) and Raymarine's WAAS-GPS receiver built into the
GPS antenna. The RL70CRC NMEA output has data from all of these
inputs.....port 1

Port 1 has a toggle switch that switches port 1 to a Garmin 185
GPS/Sonar Chartplotter in case there's Raymarine problems. The
Garmin's less accurate GPS receiver, uncompensated by WAAS or MF
differential, provides backup navigation GPS data to The Cap'n and
autopilot.

Yeoman XL Sport (disassembled and affixed to the bottom of the chart
table lift top) which outputs new waypoints to the system from paper
charts it also keeps updated SO easily.......port 2

B&G "Network" instrument string: Network Wind, Network Speed, Network
Depth, Network Data and the new Network Pilot autopilot with its own
compass fluxgate (redundant)......port 3 (NMEA0183 comes out of pin 4
on any B&G Network instrument of all the data instuments.)

Icom M602 DSC VHF radio.....outputs NMEA data to all instruments from
any distress call or call to our MMSI on Ch 70 to pinpoint emergency
or calling station's position on all chart plotters.

These ports output data directly to the TX output fed to the
computer's RS-232C serial port, when the computer is running. The
Cap'n digests this information and outputs to the B&G Network Pilot
when the master data output switch is in Computer position (another
toggle switch). The switches other position takes data directly off
the TX port on the multiplexer so the Raymarine or Garmin chart
plotters can control the autopilot if the computer is not online with
their own waypoint data steering the boat.

If the multiplexer fails, a third toggle switch takes data directly
off either the Garmin or Raymarine chartplotters and feeds it to the
network master output, without the "fluff" instruments unnecessary for
simple waypoint navigation if more stuff fails. No time to rewire at
sea. Toggle switches are labeled and instantaneously able to bypass
many dead or malfunctioning equipment in that squall line.

My handheld GPS is always loaded, just in case the whole thing is
toast!

We've also got a sextant, if it comes to that......(c;



On Tue, 21 Oct 2003 16:51:16 GMT, "Gabriel Latrémouille"
wrote:

Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated

Gaby




Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

YOn Tue, 21 Oct 2003 16:51:16 GMT, "Gabriel Latrémouille"
tempted fate with:

Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated

Gaby

Gabriel -

You've lumped several questions together. Rather than try to tell you
what to buy, let me suggest some things to think about first.

1. List all your equipment needs. For instance, you don't mention an
autopilot, which would be a critical consideration.

2. List all your display needs, for instance, do you need instrument
repeaters at the nav station? Is your GPS a chart plotter? How
important is it to have access to charts on the computer? Do you have
a flybridge?

3. If you have an autopilot, will it be driven by a chart program, by
the GPS directly, or do you want to have a choice? For instance,
after having used several PC charting packages, I would never
willingly go back to entering waypoints on the GPS. Nevertheless,
since PCs aren't that reliable compared to a good GPS, I feel it is
critical to be able to fall back to GPS waypoints if the PC fails.
Other people no doubt have other preferences.

4. Would you like to use the PC itself as a repeater display of NMEA
data? Will there be other downstream NMEA data consumers?

5. Be sure you understand the nature of the instrument interfaces you
are using. Are all the devices really using NMEA, or are there some
instruments using SeaTalk in the mix? For instance, my Raymarine
autopilot can run off NMEA or SeaTalk data, but the remote is a
SeaTalk device.

6. Are all the NMEA instruments actually following the specification
exactly? The spec is supposed to be built on RS-422, which has
several benefits. Computer serial ports use RS-232, which is similar
enough to RS-422 for the two to work together, usually. But it is a
bad idea to do this, in my opinion. You really should use a convertor
between the two types of circuits. RS-422 to RS-232 convertors aren't
all that expensive when compared to a fried motherboard on your PC.
The critical feature to look for is isolation, often referred to as
opto-isolation or galvanic isolation. A simple convertor goes from
one NMEEA circuit to one serial port. A multiplexor combines several
NMEA circuits into one serial port. If you select a multiplexor, make
sure it has the isolation feature. I believe that Meindert's have
this. Their specifications generally seem superior to other units on
the market, but I haven't actually used one. I went with a software
solution instead.

To make it more complex, not all NMEA instruments are actually using
RS-422. For instance, my Garmin handheld actually uses RS-232 and has
a typical serial port connector, so no convertor is necessary. My
depth sounder and knotlog seem to be using some sort of hybrid. My
autopilot is an honest to gosh RS-422 interface. When you look at the
wiring instructions, if you see a +, a ground, and a signal wire, you
aren't looking at RS-422. If you see a +, a ground, a signal +, and a
signal -, you have an RS-422. Again, I would never hook an RS-422 and
an RS-232 circuit together directly. Your mileage may vary.

7. To send the GPS signal both to the PC and and the radar, do you
want to split the signal before the PC, or forward the data to the
radar from the PC? Technically, you are supposed to be able to drive
up to 4 NMEA "listeners" from a single NMEA "talker" but I have never
actually done this. You can also buy an NMEA expander which is
designed to drive multiple NMEA circuits, but I think this would be
overkill. Some multiplexors have an NMEA talker port as well as a
serial port, which should work well for you. Don't forget to feed the
autopilot, though.


Just for fun, this is how my NMEA network is rigged.

My GPS (Garmin 48) is plugged directly into a serial port

My DS/KM/Wind is wired to the input side of a B&B NMEA-Serial
convertor.

My autopilot is wired to the output side of the convertor.

The convertor is attached to my laptop USP port via a serial-USB
adapter.

The data from the two serial ports is multiplexed and displayed by my
software. (You could replace this with a hardware multiplexor
attached to one of the ports). Itt displays the data on the PC screen
in nice big numbers that I can see all the way out to the cockpit.
It logs the data to disk.

That's the normal setup. When I want to use the ECS (charting
program) and the autopilot, the wiring stays the same, but the GPS is
attached directly to the ECS. The ECS passes the GPS data and the
autopilot strings it generates through a virtual serial port to my
software, which multiplexes the data with the DS/KM/wind data and
passes the autopilot commands out the USB port to the convertor and
thence to the autopilot.

If the PC was to die, I would unplug the GPS from the PC, and plug it
to the convertor using the gender changer thoughtfully secured to the
convertor.

I tell you all this not as a recommendation for you to follow, but to
illustrate the thought process behind the network configuration. I
hope I haven't confused the situation unnecessarily. It's a beautiful
thing once you get it all working. If you think it through
beforehand, you can save yourself a lot of rewiring, not to mention
you can buy the right equipment the first time.


__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at worldwidewiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/

I have used the Noland and ultimately decided upon the
MiniPlex-41USB from www.shipmodul.com. Far superior
to the Noland in my opinion. If you want a Noland multiplexer
and expander, I'll make you a good deal on them They can
somewhat handle your NMEA and also heat a compartment
as well.

Doug
s/v Callista

"Gabriel Latrémouille" wrote in message
. cable.rogers.com...
Has anyone connected several NMEA devices together?
Here is what I am planning.

GPS NMEA output to
1-PC-serial port for navigation software
2-radar to display next waypoint on radar

multiple NMEA capable instruments to
- PC for display within navigation software

Any comments suggestions appreciated

Gaby

"Glen Wiley Wilson" wrote in message
news
snip

If you select a multiplexor, make
sure it has the isolation feature. I believe that Meindert's have
this.

That's right. And beware of the new 'improved' model of Noland: this one has
NO galvanic isolation.

To make it more complex, not all NMEA instruments are actually using
RS-422. For instance, my Garmin handheld actually uses RS-232 and has
a typical serial port connector, so no convertor is necessary. My
depth sounder and knotlog seem to be using some sort of hybrid. My
autopilot is an honest to gosh RS-422 interface. When you look at the
wiring instructions, if you see a +, a ground, and a signal wire, you
aren't looking at RS-422. If you see a +, a ground, a signal +, and a
signal -, you have an RS-422. Again, I would never hook an RS-422 and
an RS-232 circuit together directly. Your mileage may vary.

In general: you can connect a RS-232 output to a NMEA RS-422 input by
connecting teh TX or OUT from the RS-232 to the + or 'A' from an NMEA in,
while connecting the - or B from NMEA in to the ground of teh RS-232 output.
The other way around (RS-422 out to RS-232 in) will mosty not work.

Meindert

Doug,

I just had a look at the ShipModul site and read the info concerning both
the VirtualPlex-1 software and the MiniPlex-41USB. Both sounded VERY
interesting. Could you tell me if purchasing the MiniPlex-41USB includes the
VirtualPlex-1 S/W? Is the S/W usable without the hardware? Lots of people
seem to be having trouble simply attaching a GPS receiver to their laptops
because they have no serial ports anymore. It seems to me that the
VirtualPlex-1 SW solves that problem as well.

Any enlightenment will be appreciated.

TIA

Vic

--
__________________________________________________ ______

Victor Fraenckel - The Windman
vfraenc1 ATSIGN nycap DOT rr DOTcom
KC2GUI

Home of the WindReader Electronic Theodolite
Read the WIND

"Victory at all costs, victory in spite of all terror, victory however long
and hard the road may be; for without victory there is no survival."
- Winston [Leonard Spencer] Churchill (1874 - 1965)

Dost thou not know, my son, with how little wisdom the world is governed?
-Count Oxenstierna (ca 1620) to the young King Gustavus Adolphus

"Vic Fraenckel" wrote in message
...
Doug,

I just had a look at the ShipModul site and read the info concerning both
the VirtualPlex-1 software and the MiniPlex-41USB. Both sounded VERY
interesting. Could you tell me if purchasing the MiniPlex-41USB includes
the
VirtualPlex-1 S/W? Is the S/W usable without the hardware? Lots of people
seem to be having trouble simply attaching a GPS receiver to their laptops
because they have no serial ports anymore. It seems to me that the
VirtualPlex-1 SW solves that problem as well.

Any enlightenment will be appreciated.

Hello Vic,

I am the manufacturer of both poducts. The VirtualPlex-1 software is not
included in the purchase of a MiniPlex-41USB. VirtualPlex-1 is usable
without the hardware, it can be used with any source of NMEA data. But
VirtualPlex-1 does not solve the problem you describe.

The MiniPlex-41USB connects four NMEA sources to a computer that lacks a
serial port. When you only have to connect a single GPS, it is a bit of
overkill since a simple USB-serial converter could be used for this purpose.
However, many of these converters do not work very well or create the famous
wild-mousepointer problem. This does not occur when you use a
MiniPlex-41USB, because the supplied driver blocks any Plug&Play requests
coming from Windows.

VirtualPlex-1 could be described as the software antipode of a multiplexer.
It reads the data from one single serial port, beit a real one or a virtual
one, and dispatches it to up to 255 virtual serial ports that are created by
VirtualPlex-1. This enables multiple software applications to run at the
same time and use the incoming NMEA data. Also, VirtualPlex-1 allows the
applications to talk back to the 'real' serial port in order to send out
NMEA data.

Hope this clarifies things a bit.

Meindert
www.shipmodul.com