Lowrance to B&G NMEA

[Heckler]

I fitted my Lowrance 5150c last year, put the NMEA output to the Raytheon radar and Silva DSC radio ad bingo it all worked, position on the radio, speed, cross track error etc on the radar. I also tried putting it to the B&G pilot head, as soon as I did that the stuff going to the radio and radar stopped and "no NMEA" error on the pilot. Last weekend I thought I would get to the bottom of it, I tried all sorts. I even connected the plotter alone direct to the pilot head, nothing! I tried different baud rates, all that did was stop the radio and radar displaying data. I put a volt meter on the output of the Lowrance, it was .7 to 4 volts, ascending in sequence, when I connected it to the B&G it dropped to 1.9v max, again sequencing from lo to hi. Interesting that when it was connected to the radio and radar it did the same voltage wise, but they displayed the data.
Again when connected to all 3 OR just to the B&G it seemed to stop the data in its tracks. So it would appear that the B&G is stopping data coming out. I did try reversing the connections, still nothing.
Any thoughts anyone?
Stu

 

[Playtime]

So it would appear that the B&G is stopping data coming out. I did try reversing the connections, still nothing.
Any thoughts anyone?
Stu

I have no direct experience of the kit you're using but it sounds as though the input to the B&G is overloading the output from the Lowrance.

IIRC, a NMEA talker (the Lowrance here) can drive up to 4 NMEA listeners. You are loading it with 3 listeners (radar, DSC and B&G), therefore, in theory, it should be OK.

Have you any other NMEA talker you can connect to the B&G (like a HH GPS maybe?). If that doesn't work then it strongly indicates the input to the B&G is duff.

Do you have any specs for the NMEA output and inputs or do they just reference the NMEA spec?

 

[Heckler]

I have no direct experience of the kit you're using but it sounds as though the input to the B&G is overloading the output from the Lowrance.

IIRC, a NMEA talker (the Lowrance here) can drive up to 4 NMEA listeners. You are loading it with 3 listeners (radar, DSC and B&G), therefore, in theory, it should be OK.

Have you any other NMEA talker you can connect to the B&G (like a HH GPS maybe?). If that doesn't work then it strongly indicates the input to the B&G is duff.

Do you have any specs for the NMEA output and inputs or do they just reference the NMEA spec?

Thanks for the input, the Lowrance just says NMEA 18something 2000, but I can plug my Garmin 12 in to see if that will deliver
Stu

 

[hightech]

Simple,you need an NMEA buffer, all the loads you are trying to attach are killing the signal

 

[Heckler]

Simple,you need an NMEA buffer, all the loads you are trying to attach are killing the signal

Thanks
I did try it direct if you read the original post
Stu

 

[Playtime]

Thanks for the input, the Lowrance just says NMEA 18something 2000, but I can plug my Garmin 12 in to see if that will deliver
Stu

If the Lowrance is delivering NMEA 2000 that could well be the problem. I suspect the B&G unit takes 'old flavour' NMEA (0183) not the latest 2000 protocol which is based on vehicle CANBUS technology. See here.

Umm - ignore the above. Just checked the Lowrance spec here and it appears to NMEA 0183.

Try the HH input to the B&G.

 

[Heckler]

If the Lowrance is delivering NMEA 2000 that could well be the problem. I suspect the B&G unit takes 'old flavour' NMEA (0183) not the latest 2000 protocol which is based on vehicle CANBUS technology. See here.

Umm - ignore the above. Just checked the Lowrance spec here and it appears to NMEA 0183.

Try the HH input to the B&G.

Thanks again
the lowrance is NMEA 0183 but I seem to remember 2000 after the 0183. It definitely isnt the canbus technology, the raytheon radar is as old as the B&G (1999) and that talks ok. Will try the HH next weekend
Stu