Garmin gWind issues

[hjohnson]

Originally Posted by brccd

hjohnson:
so, just to be clear...did you use a 1200 ohm or a 120 ohm resistor for termination?

could give this a try...

thx
Bert

120 is what is what we did. Just make sure you get it between the two data wires (ie not the one carrying 12V and not the shield) and give it a whirl.

[hjohnson]

Originally Posted by John_Trusty

I’m solving my bad Garmin wind indicator by replacing the whole works with B&G. I applaud hjohnson for figuring out Garmin’s technical issue, but I’m too old to solder bits into a system that was poorly designed. Chalk it up to lessons learned and their bad reputation, and move on.

I hear you. In our case, our mast cable comes into a terminal strip at the bottom of the mast, so we added the resistor at the terminal strip, so easy peasy no soldering required.

[brccd]

sorry...saw its a 120 ohm resistor...will give it a try...
Thanks,
bert

[johnny_buddha]

Originally Posted by hjohnson

Try adding a 120Ohm resistor across the data pair on the nexus bus. That stabilized the system on our boat. If you use your multimeter, the shield is ground, one of the pins will be +12v, and the other two will be the data pair.

We are experiencing this same issue: wired gWind transducer not sending data, no light on the Nexus port on the GND10. Swapped out the GND10 for a new one, same condition.

Can someone please explain like I'm five (ELI5) what is involved with

adding a 120 ohm resistor across the data pair

means?

I've done a small amount of electrical (12V wiring of fans, bilge and washdown pumps, lights) and electronics (Arduino circuits) work, but I don't understand where/how I'm supposed to add a resistor on the Nexus cable/circuit.

Thanks, in advance.

[RubiconAg]

Originally Posted by johnny_buddha

We are experiencing this same issue: wired gWind transducer not sending data, no light on the Nexus

I have the same question as you and would like confirmation on this. I vaguely understand communication systems: The GND 10 has the ability to run 2 nexus accessories (one being the mast cable connection to the Gwind transducer) and the other port being left unused. I am thinking of using a spare field connector and installing a 120 ohm resistor between the two pins for the data connections, then plugging that connector into the spare nexus port on the GND 10. If I am following this conversation correctly, its similar to the NMEA backbone needing the "end caps" at each end, which are essentially resistors in the communication circuits of the NMEA backbone. This resistor in the nexus communication circuit (which is essentially the mast cable/gwind/spare port on GND 10) helps "terminate" the Nexus communication circuit at the GND 10 so it stabilizes with only the Gwind connected.

I hope hjohnson will confirm my assumption!

[hjohnson]

Originally Posted by RubiconAg

I have the same question as you and would like confirmation on this. I vaguely understand communication systems: The GND 10 has the ability to run 2 nexus accessories (one being the mast cable connection to the Gwind transducer) and the other port being left unused. I am thinking of using a spare field connector and installing a 120 ohm resistor between the two pins for the data connections, then plugging that connector into the spare nexus port on the GND 10. If I am following this conversation correctly, its similar to the NMEA backbone needing the "end caps" at each end, which are essentially resistors in the communication circuits of the NMEA backbone. This resistor in the nexus communication circuit (which is essentially the mast cable/gwind/spare port on GND 10) helps "terminate" the Nexus communication circuit at the GND 10 so it stabilizes with only the Gwind connected.

I hope hjohnson will confirm my assumption!

The one thing I’m not sure of is whether the two Nexus ports on the GND-10 are two ports on the same bus, or two independent nexus busses. If they’re both on the same bus, then yes, creating a termination plug for the unused port would work.

You could confirm this with a multimeter. If you have continuity between the data pins on the two ports, then they’re on the same bus.

If they’re independent busses, then a termination plug won’t help, and you’ll need to add the resistor to the field connector that connects the wire running up the mast.

I can’t check this myself, as I’m currently 8000 miles from my boat.