Connecting new GPS to Navnet1834C

[SailorLinda]

I have a Navnet 1834C chart plotter which is an awesome unit, but now I have a problem with the GPS. It is a long story but basically the Furuno GPS is gone and I have had to replace it with a Garmin GPS - the only one available at this time and location. I have read many forums on line and it seems like I should be able to splice the Garmin wires to the Furuno wires (which are still intact and are "plugged" into my chart plotter).

Ignoring the red and black power and ground wires the Garmin manual shows colours of the wiring as:
white/orange Rx/B(In-)
white Rx/A (In+)
Gray Tx/A (Out+)
white/red Tx/B (Out-)

From the Furuno manual
The colours of the Furuno wiring are
White TDA
Blue TDB
Yellow RDA
Green RDB
And the manual states that RDA and RDB (yellow and green wires) are the input for the Radar/plotter.
I am connecting the Garmin Gray and white/red wires to the Furuno yellow and green wires.
The 12 volt power is on (tested with a volt meter).

This splicing I have done is not working for me.
When I check the sentences for Port 1 on the port monitor they are garbage, no info at all, just random symbols and letters. And when I check the signal for the GPS it shows me no satellites are found.

I need help. Without a GPS input my Furuno chartplotter is non-functional. Any suggestions are welcome and I will try them. I cannot purchase a Furuno GPS from my cruising location so that is not an option.

Sailor Linda

 

[TheReaper]

The wiring appears to be correct. The next thing to look at is under Menu-System Configuration-Nav Option-Nav Source Setting to ensure that the position source is set to "ALL". You mentioned that that port monitor is showing "garbage" which usually means that the baud rates are mismatched or that there's noise on the data lines. Ensure the baud rate for Port1 matches the required Garmin baud rate. If the Garmin antenna is going to work, then doing those things will allow it to. It's possible that the Garmin only works in a proprietary mode which would not work with the 1834C. You'd have to ask Garmin about that. Normal NMEA0183 should work fine on our system. The only other possibility that I can think of is that a software update on the 1834C may be necessary.

If it still doesn't work after that, then I'd consider another GPS antenna/navigator that is compatible with NMEA0183 v1.5 or 2.0. You mentioned that purchasing a Furuno product is not possible, but for others that may read this post, the GP330B/0183 would plug right in to Port1 and work.

 

[SailorLinda]

The wiring appears to be correct. The next thing to look at is under Menu-System Configuration-Nav Option-Nav Source Setting to ensure that the position source is set to "ALL". You mentioned that that port monitor is showing "garbage" which usually means that the baud rates are mismatched or that there's noise on the data lines. Ensure the baud rate for Port1 matches the required Garmin baud rate. If the Garmin antenna is going to work, then doing those things will allow it to. It's possible that the Garmin only works in a proprietary mode which would not work with the 1834C. You'd have to ask Garmin about that. Normal NMEA0183 should work fine on our system. The only other possibility that I can think of is that a software update on the 1834C may be necessary.

If it still doesn't work after that, then I'd consider another GPS antenna/navigator that is compatible with NMEA0183 v1.5 or 2.0. You mentioned that purchasing a Furuno product is not possible, but for others that may read this post, the GP330B/0183 would plug right in to Port1 and work.

Thank you for the reply. I will investigate further and I will write to Garmin. The marine store where I purchased the Garmin GPS knows nothing. I have already updated the Furuno 1834C wirh the latest software possible. How do I check the Baud rate on Port 1? On Ports 2 and 4 there is a setting for Baud rate but I do not see that line item when I look at the Port 1 monitor.
Sailor Linda

 

[TheReaper]

You are absolutely right. My mistake. Port 1 is fixed at 4800 baud. You can actually just move the cable from Port 1 to Port 4 and try the 19,200 baud rate setting to see if the antenna works in the high speed mode. If not, that only leaves verifying the baud rate coming out of the Garmin antenna to see if it can be changed to either 4800 or 19200.

 

[SailorLinda]

I have just chatted with Garmin support and confirmed the output Baud rate from their antenna is 4800, so that is compatible. They say the NMEA sentences are not proprietary. I am not on the boat today so cannot check anything else. It may be a few more days befire I respond again. Thanks