Can FI70 use SOG as data source for apparent wind calcs?

[dig090]

Howdy:

Sorry if this is a repeat question. I did some searches on the forum (and the interwebs) and couldn't find a specific answer to this question.

Right now I have the FI501 which I like but I'm always frustrated with it not being able to use SOG for the apparent wind calculation. I can never get my paddlewheel to function for more than a week it seems so my SPD is always 0. Sigh.

As I read the FI70 manual there is an option for "data source for the speed thru water". Does this allow me to set it to SOG and does that impact the apparent wind calculation? Has anyone tried this?

Thanks much!
gray

 

[Magnetron]

Yes, just maybe not "set" though. The FI70 has as a part of it's programming automatic data source switching which can effectively failover to SOG.

If in a boat :sail I have two sources of ship's speed: STW provided by a paddlewheel and SOG provided by the GPS -

In general, STW is always going to be the more accurate source of speed because it's analog so if the STW data is somehow being transmitted to the network - it will always have highest priority. However, if no STW data is present the FI70 is able to continue calculating TWA/TWS via GPS.

Hope this answers the question, :sail

- Maggy

 

[dig090]

Thanks Maggy. So what happens when STW is being published as 0 and SOG is being published as 6 knots? It will use 0?

Have you tried setting the data source for STW? According to the docs there is configuration option for that.

gray

 

[Magnetron]

So what happens when STW is being published as 0 and SOG is being published as 6 knots? It will use 0?

I physically remove the device's connection to the NMEA2000 backbone network at the tee and leave it to dangle there, than only the SOG from GPS is present for the data repeaters to use.

- Maggy

 

[dig090]

Yeah that doesn't work for me because it is coming out of a depth/water-temp/paddlewheel multi-sensor.

Trying to see if I can configure the FI-70 to specifically ignore the STW and use the SOG for it's apparent wind calcualtions.

 

[Magnetron]

Yeah that doesn't work for me because it is coming out of a depth/water-temp/paddlewheel multi-device.

So is what you have one of Airmar's DST-810 Smart Sensors? If so, have you contacted Gemeco about how to turn on/off NMEA STW sentences using the app and bluetooth?

Otherwise, the better solution might be to keep the FI-501 and pick up a DST-810 where this feature is supported.

Hope this helps, :sail

- Maggy

 

[capdave]

Just to clarify - your wind sensor is giving you Apparent Wind, that's all it can do. Boat speed and heading are used to calculate True Wind. I've also wrestled with this issue, and the answer is to pull your paddlewheel and clean it once a week if that's what it takes. That's what I do, only takes 3 minutes.