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Larry W4CSC
 
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Default NMEA Multiplexing ?

Since I posted last, I called the engineering company down in Florida
because the multiplexer had no output on its TLK terminals with all 4
ports full of active data. TX had data out to the computer great,
though.

This unit was designed with The Cap'n in mind, i.e. to have the
computer online all the time. The company explained to me that if I
wanted to use the multiplexer without the computer, I'd have to
connect my NMEA listeners to the computer port TX line, not the NMEA
output which is but a level converter/repeater for the RX port coming
back from the computer. He also warned me there was only 15ma of
current available, but all my listeners are very high impedance so
that's not an issue, so far.

So, I added yet another DPDT mini toggle switch to switch the Master
Network Output between the TX terminal and the TLK terminal, depending
on whether you want to use the computer's output, or save power and
use the multiplexer's output direct without computer intervention.
Works great. You can even have the computer online "watching" and
computing as a listen, with the system ignoring its processed output
because it isn't hooked to anything.

GPS SOURCE now has two switches....Computer? (Y/N).....and.....Garmin
GPS or Raymarine display (radar, gyrocompass, WAAS-GPS).

I thought I was going to have a conflict over depth because the Garmin
has depth output from its own sonar plotter, but so does the B&G Depth
instrument on the panel. The system seems to like the Garmin better
when the switch is in the Garmin position, displaying that on the
Raymarine, for instance, then using the B&G Depth output when the
Garmin is not switched in and it's the only thing available.

I've also gotten a chartplotter point from a DSC emergency on Channel
70 on the Raymarine chart plotter display. The bridge was blocking
the radar in his direction so I didn't see an echo from him but his
lat/long was indicated properly. Radio is the Icom M602 DSC VHF from
the mainmast 3db Shakespeare at 55 ft up.



On Sat, 13 Sep 2003 14:12:19 -0700, "Steve" wrote:

Yah! It should be and I suspect I may have a wiring error from the serial
Data Out or Data Com. going to the interface.

The interface just sits in 'idle' mode with the red and green led flashing,
waiting for a XTE.

I may just try hooking the interface directly to the GPS and see if it will
recognize the XTE from the there..

I don't want to steer or control the AP from the GPS since it is too
difficult to program in the WPs and Routes. (being an older gps that I can't
upload these from the laptop.)

Thanks for the reassurance.. means I should check my wiring, etc.

Steve
s/v Good Intentions




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?