NMEA expert anyone?

Daniel · 12 February 2004, 00:08

I'm trying (infact i've been trying for 3 months) to install an NMEA repeater into the RIB. This will allow me to see COG, SOG, Depth etc. etc. on a large digit display at a glance.

The garmin outputs NMEA data, it works, because both the engine instruments and VFH receive it.

I bought a cheap Navman repeat 100, connected it up and followed the procedure to detect NMEA sentances but it would not work. Becasue it was cheap i decided it might be faulty.

I bought a Navamn repeat 3100, wired it up all correctly and followed instructions to detect NMEA sentances available... still nothing.

I know the garmin is transmitting OK, i have even downloaded a program for the PC which displays this NMEA data for me.

Anyone any ideas? Both claim to be NMEA 0183 compatable. There are no further settings.

stevetheboat · 12 February 2004, 06:18

Hi Daniel,

You say that your vhf and other instruments are receiving data from the Garmin unit OK?
If this is the case, I think if you check out the handbook, you will find that the Garmin will only run a total 3 nmea links.
So if the repeater is the 4th link this will not function.

Hope you find this of some help.

Regards,

Stevetheboat

(Duct tape is like the Force. It has a dark side, it has a light side, and it holds the Universe together.)

Daniel · 12 February 2004, 08:43

Cheers, but i have tried disconnecting the other devices, and the navman is only the 3rd device.

Mark Halliday · 12 February 2004, 10:36

Daniel
You have probably been here, but if not try:-

http://www.navman.com/assets/marine/...Eng_medres.pdf

It may giveyou a few more pointers.

Garygee · 12 February 2004, 21:34

Hi Daniel

All NMEA outputs have limited drive capability, but if you exceed this and the ouptut if not capable of driving all the inputs I would expect some of the others to stop working as well.

NMEA 0183 can be run a different baud rates, the normal one is 4800 but some items use 1200 and 9600 baud.

It may be worth seeing if the repeaters can be set to different baud rates.

Also it is likley they are using the $GPRMC string, but see if you can select what NMEA sentence it is set to receive.

Failing all this try the manufacturer

Regards Gary

Cookee · 13 February 2004, 10:14

Probably already tried it but the GPS should be on the white wire?

Daniel · 17 February 2004, 22:11

OKay, thanks to all those who have made suggestions, i've solved it this evening.

Mark, it's not a navbus system i am trying to connect, although the Navman Repeat 3100 does repeat the navbus data it is also sold as an NMEA repeater - which is what i want.

Gary, you, indirectly held the solution... contact the manufacturer. I had already tried looking and checking for baud settings, all non-changable 4800.

Cookee, you could not be more wrong... that's what the manual says but having got some feedback from Navman they misprinted the manual!!!!!

The first NMEA input is green, the second yellow and the third white, and they must be used in this order. In the book of words it says white, yellow then green - which of course i had followed.

Hope this helps someone else one day!

Cookee · 18 February 2004, 09:20

Of course if you had followed my usual way of doing things it would have been resolved ages ago "If everything else fails read the fu$%&$g manual!" Of course this done occasional result in a few singed wires and extra expense but no-one said life was simple!