FI-50 True wind problem

[capdave]

I have a Navnet 3D network with two MFDs and lots of FI-50 instruments connected.

The wind instruments have stopped calculating/displaying True Wind speed/direction - they only display Apparent Wind speed/direction on both True and Apparent settings. But I have a text box on one of the NavNet 3D MFDs that continues to properly calculate/display True Wind speed/direction.

The FI-50 instruments are also displaying 0 SOW - paddlewheel cleaned, still 0. All SOG displays are correct.

I can't find any way to force the instruments to make the True wind calculation using SOG, and I don't understand why the MFD text box correctly shows True Wind and the instruments don't.

Suggestions??

 

[kicker]

The FI-50 instruments are also displaying 0 SOW - paddlewheel cleaned, still 0. All SOG displays are correct.

What is SOW?

Is the FI50 showing dashes or zeros? If you see three dashes, we are missing speed data.

 

[Pthein]

I think he means STW

 

[capdave]

My instruments use SOW to designate speed through the water. The display is 0.00.

But why does the MFD work??

 

[kicker]

My instruments use SOW to designate speed through the water. The display is 0.00.

But why does the MFD work??

I have never heard of a NMEA sentence "SOW".

Let me try to get a little more information from you. So your MFD's are showing true wind speed but is it not showing on any of the FI50 displays? Any many do you have exactly?

Are you able to display apparent wind speed or angle on the MFD's and FI50's?

What is your heading source and how is it connected into the system?

Is your paddle wheel NMEA0183 or NMEA2K sensor?

 

[capdave]

See below for some replies:

Let me try to get a little more information from you. So your MFD's are showing true wind speed but is it not showing on any of the FI50 displays?

* That's correct

Any many do you have exactly?

* Eight - three of them are Wind displays

Are you able to display apparent wind speed or angle on the MFD's

* Haven't tried, not programmed into any text box or graphic right now

and FI50's?

* Yes the FI50 wind instruments are showing apparent wind speed/angle

What is your heading source and how is it connected into the system?

* The system has an SC-30 satellite compass which the system diagram says has an N2K connection to the DRS-4D radar, which in turn has an ethernet connection to a Hub 101, which both MFD12s connect to. The diagram says the master MFD puts out an N2K signal to the FI50 instruments. There is also a PG500R fluxgate compass/gyro which according to the diagram has only an 0183 connection to the FAP5002 autopilot.

Is your paddle wheel NMEA0183 or NMEA2K sensor?[/quote]

* The boat actually has two paddlewheel/depth transducers I discovered yesterday. The diagram shows a 525STID-MSD connected to a DFF1, which is then connected by ethernet to the Hub 101. When I bought the boat I was told the DFF1 doesn't work. There is a second "Airmar" paddlewheel/depth transducer which doesn't appear on the diagram, and I don't know how it connects to the system at all.

It's the Airmar paddlewheel that I cleaned - thinking the other transducer was depth only and didn't work. Then on a swim I saw it also has a paddlewheel. I think the next step is to clean that paddlewheel, but I can't pull the transducer out from inside the boat - won't budge. I'll dive and clean it in the next couple days. Worse case we have a haulout in 3 weeks.

 

[kicker]

For FI50's to display TWS (true wind speed) or TWA (true wind angle), it needs AWS (apparent wind speed) and AWA (apparent wind angle) and speed. So AWS + AWA + Speed = TWS/TWA.

I think we are just missing a piece of data.

 

[capdave]

Well we did a quick scrub on the 525STID-MSD paddlewheel, and went sailing. That fixed the problem, got both speed through the water and true wind on the instruments.

But it begs the question - why can't I set the instruments to use SOG to calculate True?? Obviously the MFD does as it calculated True without the paddlewheel.

 

[Johnny Electron]

The FI50s are sailboat instruments which are no longer sold. Many as such was designed to use STW for speed and calculations. There might be newer software depending on what FI50 instrument you are discussing. If you have newest software and it won't work off SOG, then you must have STW for the calculation.