Connections: Nasa Ais radar to Garmin GPSMap 550

underdog

underdog

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Help Trying to connect Nasa AIS Radar

Have connected the Radar to a battery lights up ok but states no GPS Position. 3 other wires of which handbook says:
Red = Alarm
Black = Alarm
Blue = NMEA output from GPS

With the Garmin GPSmap 550 I have a multiple choice of cables to attach to the Ais radar Blue cable.
Excluding the red and Black cables which are attached to the Battery
There are as follows marked on a label
Orange:AC/on
yellow: Alarm
Grey: P2XD
Violet: P2RXD
White :Can High*
Green : Can Low*
Brown: P1RXD
Blue : P1TXD

Which of these should be connected to what to get the GPS to interact with the AIS Radar?
Hoping some one can help before I chuck the whole lot in the bin!
 
Don't lob the whole lot in the oggin.

The NASA AIS don't look much, but it is, in my view, a superb bit of kit at sea.

I managed to get mine going so it can't be that hard. The alarm outputs are just for fixing an external buzzer.

I know little, but - my best guess is that you should try the blue output from the Garmin first and if that fails the grey. You may need to configure the output in the Garmin menu to get it squirting in the right direction.

In a bit, someone who knows will be along.
 
Last edited:
underdog said:
Help Trying to connect Nasa AIS Radar

Have connected the Radar to a battery lights up ok but states no GPS Position. 3 other wires of which handbook says:
Red = Alarm
Black = Alarm
Blue = NMEA output from GPS

With the Garmin GPSmap 550 I have a multiple choice of cables to attach to the Ais radar Blue cable.
Excluding the red and Black cables which are attached to the Battery
There are as follows marked on a label
Orange:AC/on
yellow: Alarm
Grey: P2XD
Violet: P2RXD
White :Can High*
Green : Can Low*
Brown: P1RXD
Blue : P1TXD

Which of these should be connected to what to get the GPS to interact with the AIS Radar?
Hoping some one can help before I chuck the whole lot in the bin!
Click to expand...

Underdog,

from my gut feeling (not having any manuals to look at) I would connect the blue output from the NASA Ais to the brown input of port 1 (RX) of the Garmin. Make sure, to set the Garmin port 1 to the right speed setting. AIS is high speed NMEA (something like 37200kbs) but check both manuals.

Good luck!

Findus
 
Underdog..

From your description of the Garmin you should be able to take the NMEA output from the GPS on either the Grey (Port 2 Tx data) or the Blue (Port 1 Tx Data) wire.

Both the units will share the same negative so will not need to worry about that.

Data speed - AIS is at 38400 but this is purely a GPS NMEA signal so should be output at the standard NMEA 4800 baud.

(The higher 38400 speed is only really used for output from an AIS receiver into perhaps a chart plotter)
 
Thanks for the input.
However still not able to have them communicate with each other.I have tried all sorts of permutations.Have rung both Garmin and Nasa support lines.Each blames the others set up.
Any suggestions as what to do next
 
underdog said:
Thanks for the input.
However still not able to have them communicate with each other.I have tried all sorts of permutations.Have rung both Garmin and Nasa support lines.Each blames the others set up.
Any suggestions as what to do next
Click to expand...

Connect the Garmin's blue wire (NMEA0183 Port 1 output) to the Nasa blue wire (GPS input). Go into the Garmin communications set-up (Configure >Communications) and set Serial Port 1 to "NMEA Standard".

If the GPS position still isn't being received, go back into the Garmin's communications set-up, select "NMEA0183 Setup", select System, and try setting different numbers of digits in the "Posn Precision" options.
 
"However still not able to have them communicate with each other.I have tried all sorts of permutations.Have rung both Garmin and Nasa support lines.Each blames the others set up."



This sounds familiar to me.

I had a similar thing, though a different plotter and different company. It ended up working upside down, in that the "correctly" configured output did not work. I ended up ringing the help line to tell them how I sorted it out.

I think pvb is setting you on the right lines.
 
From dim memory, the baud rate of the GPS wants setting to 9600.
You want one of the Tx (transmit) wires from the GPS.
That and what pvb says!
 
Have solved the problem.
Despite trying all the suggestions I still could not get the Garmin chart plotter to talk to the Nasa Ais.
However I also have Furuno GPs31 Navigator on board.Having read the hand book
I was able to get it to communicate with Ais radar after 10 minutes trying different settings.
Without the input of other forumites I might still be struggling.So many thanks.
 
Well done.. One thing I did think is that perhaps the Garmin was not set to send the correct sentence within the NMEA output stream.

There is a setting somewhere on it where you can choose to enable or disable various sentences (information packets) within the outgoing NMEA stream.

The Garmin manual does not say which sentences are enabled by default but the NASA needs the RMC sentence. Worth a check perhaps.
 
The NASA AIS Radar ( the one with the display) does not have an NMEA output only the AIS Engine has an output. The GPS is an input signal to allow the AIS Radar to fix your position i relationship to the other vessels.
 
Rogershaw said:
The NASA AIS Radar ( the one with the display) does not have an NMEA output only the AIS Engine has an output. The GPS is an input signal to allow the AIS Radar to fix your position i relationship to the other vessels.
Click to expand...

You're right, but you obviously didn't read the original post!
 
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