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?