Connect Garmin 72 to Battery Direct AND also data out to Furuno Plotter - NMEA 183

[SteveLop]

Hi, 

hopefully one of the guru's here knows the answer re NMEA 183 connections with 2 devices.

I have the Garmin Data cable connecting my Garmin 72H GPS to power using black and red wires.

I now want to connect the Garmin Data Out (Brown) to the my Furuno 620 Plotter ReceiveA (yellow) to xfer location and waypoints. I also need to connect the Garmin black wire to the ReceiveB Furuno wire (green). 

I "assume" this means I need to split the garmin black to connect to both the battery -ve and the Furuno plotter green.

Its probably a basic electronics issue however I thought I would ask.

 

Much appreciated

Steve

 

[zmk1962]

Not sure what exactly you mean by split the garmin black wire.... you need to connect the garmin black (-ve) to both the battery (-ve) and the Furuno (-ve) .. they need to have the same grounding. No waypoint information will be transmitted or received on the garmin black (-ve).

The furuno will have a receive (rx) and transfer (Tx) wire. Above you said  furuno ReceiveA (yellow).

So if you follow the diagram below:

Garmin brown (Tx) goes to furuno Yellow (Rx)

Garmin white (Rx) goes to Furuno  ?green? (Tx) please check the furuno manual.

I have included the link for the garmin below. 

https://static.garmincdn.com/pumac/GPS72H_OwnersManual.pdf

Cheers Zoran

Edited November 11, 2021 by zmk1962

[SteveLop]

thankyou Zoran, this makes sense to me 

 

This is the post (which could be totally wrong) that has confused me with advice to connect the garmin black -ve to the Furuno 620 green (rd-b receive mate for the rd-a data in) and no mention of connecting the black wires between Garmin 720 and Furuno 620. 

http://www.ausfish.com.au/vforum/archive/index.php/t-58418.html

 

Regards,

Steve

[zmk1962]

I googled the Furuno manual:

https://www.nuovamarea.com/files/product manuals/Furuno/FCV620 Operator's Manual.pdf

2 hours ago, SteveLop said:

.... no mention of connecting the black wires between Garmin 720 and Furuno 620. 

It clearly shows the Furuno has a black wire (connector 8 DC -ve ... this should be connected to the same battery -ve as your garmin (so in effect the two black wires are connected and on the same ground).

 

Now that I can see the manual it shows WHT-BLU are the Tx pair (the Blue is the ground wire for the signal), the YEL-GRN are the Rx pair (the Green is the ground wire for the signal).

So as I read it :

 

Garmin Brown (Tx) goes to Furuno Yellow (Rx). Furuno Green goes to -ve ground (back to battery -ve).

Garmin White (Rx) goes to Furuno  White (Tx). Furuno Blue goes to -ve ground (back to battery -ve).

It is what is shown in this diagram:

Note the NMEA GND wire - it just happens that the Furuno has 2 x NMEA grounds, one for the Tx and one for Rx. ... 

Cheers Zoran

[SteveLop]

thankyou Zoran, amazingly helpful...  the connection of the furuno green and blue back to the battery -ve as well is the bit that I had missed completely

I will test it all out on the weekend 

[zmk1962]

Your welcome ... now you can stop reading ausfish and focus on fishraider ... hahaha !

Look forward to some reports.

Cheers Zoran

[SteveLop]

On 11/12/2021 at 1:34 PM, zmk1962 said:

Your welcome ... now you can stop reading ausfish and focus on fishraider ... hahaha !

Look forward to some reports.

Cheers Zoran

I can report Zoran that your advice worked a treat. I connected all -ve wires (data/ power) back to the common battery -ive and the data transmits beautifully to whatever is listening.

I also felt brave and connected the GPS data out to my ICOM IC-m411 radio at the same time. 

Well it did once I went into the settings of the Garmin 72h and changed the default data output mode from Garmin (default) to NMEA  it all just worked. GOS coords on radio now and on sounder 🙂

 

thanks again.

Steve  

[zmk1962]

21 minutes ago, SteveLop said:

I can report Zoran that your advice worked a treat. I connected all -ve wires (data/ power) back to the common battery -ive and the data transmits beautifully to whatever is listening.

I also felt brave and connected the GPS data out to my ICOM IC-m411 radio at the same time. 

Well it did once I went into the settings of the Garmin 72h and changed the default data output mode from Garmin (default) to NMEA  it all just worked. GOS coords on radio now and on sounder 🙂

 

thanks again.

Steve  

Good job and thanks for reporting back. Enjoy the set up.

Cheers Zoran

[dmck]

@Zoran  I'm late in to this post so have nothing to add.... but... FYI I'm certain that FURUNO I/O's are balanced ccts, so 1 of the signal-pair wires has to be earthed to talk to most other devices.