[TG] [TG11] Recalibration of wind instrument after iTc-5 software upgrade

[tmass60]

I have recently completed software upgrades on all components in my system (see attached files) including the iTC-5 which has speed, depth, and wind connected. I performed a calibration of the wind instrument (E22078 vane style) connected via iTC-5 which was working correctly before the software upgrade.

All steps of the calibration appeared to be correct throughout the 360 deg turning process with no error messages. Waves were calm, boat speed approx. 2 knots, true wind speed 5-8 knots.

After calibration however the wind speed reading does not seem indicate wind speeds much more than 7 to 10 knots despite true wind conditions later in the day that were considerably more than this. Please advise as to the next steps of trouble shooting or calibration steps you would recommend.

Also, my vane offset after alignment calibration comes out as 172 degrees. Is it typical for this offset to be such a large amount?

Thanks,

tmass60

[Tom - Raymarine - Moderator]

Hello Tmass60,

Quote:I have recently completed software upgrades on all components in my system (see attached files) including the iTC-5 which has speed, depth, and wind connected. I performed a calibration of the wind instrument (E22078 vane style) connected via iTC-5 which was working correctly before the software upgrade.

For future reference, re-calibration is not normally required after a software update, we try hard to avoid you having to do this. The one recent exception to this is when we went from v1 to v2 Evolution autopilot software, which changed enough of the internals of the pilot's function that the old calibration values no longer applied.

Quote:After calibration however the wind speed reading does not seem indicate wind speeds much more than 7 to 10 knots despite true wind conditions later in the day that were considerably more than this.

What wind speed value were you looking at: Apparent, True or Ground wind? If either True or Ground, what does Apparent show? Apparent is directly measured, True and Ground are calculated and therefore rely on other inputs (STW, GPS.)
The Apparent Wind Speed (AWS) values should not be affected by normal calibration (which is focussed on wind angle.) There is a wind speed offset, but you should normally leave it on the default 0.7 or 0.75 factor.
Assuming the wind speed cal factor hasn't been changed, the usual reason for under-reading AWS is physical: a poor contact in the signal line, moisture in the masthead connector or electrical interference on the analogue signal wire masking some of the speed pulses.
There's no simple test for these sorts of problems: you would need to look in detail at the signal voltages on the yellow wire coming into the ITC5, but you can't do this with a multimeter (which is only good enough for a basic proof-of-life test): you'd need an oscilloscope. On the off-chance you or a friend do have a 'scope, you'd be looking for a 0 - 8V square-wave with two pulses per rotation of the cups, between yellow and shield/bare.

Quote:Also, my vane offset after alignment calibration comes out as 172 degrees. Is it typical for this offset to be such a large amount?

This is perfectly normal. The original orientation is arbitrary and the required offset could be anywhere between 0 and 180 degrees.

Regards,
Tom

[tmass60]

Hi Tom - thank you for your reply. I have a few follow-up questions but first wanted to see if you can cancel another pending similar post under "Instruments". I am a little new to the forum so wasn't sure the first one went through and did a second. I don't want anyone duplicating efforts.

Here are my follow-ups ...

Quote 1 - I did the re-calibration after the software upgrade because the wind angle was way off immediately afterwards. Boat speed also needed to be re-calibrated.

Quote 2 - this makes sense to me that the wind speed is generally unaffected by the calibration process. I could not figure out how turning the boat in circles would have any input into wind speed:) I was looking at AWS (and TWS because I was at the dock so it was the same) later in the day. The only thing I can think of that changed from pre to post software upgrade is I did physically check the iTC-5 which is loosely mounted in my nav station. Does it seem plausible at all that it could be picking up some new electrical interference if it was moved slightly?

I am separately chasing an issue with either the fluxgate compass or SG2 course computer not giving me accurate heading info.. This existed prior to the software upgrade and there were no boat speed or wind speed/angle issues (other than GWA being not shown properly if I recall correctly). I hope to solve this in the not too distant future by replacing both fluxgate and course computer with an Evolution system. In the meantime, am I correct that a fluxgate compass issue would have nothing to do with the AWA reading or TWA calculation?

Finally, as I mentioned post software upgrade my boat speed calibration was also way off. I have done that calibration as well with the five input method using SOG. I am still not 100% sure it is correct (plan to test more this weekend), but the fact both boat speed and wind speed/angle were an issue after the software upgrade do you think this is pointing more towards an iTC-5 problem as compared to the transducers themselves? Any troubleshooting steps I should consider there?

Thanks,

tmass60

[Tom - Raymarine - Moderator]

Hello tmass60,

Quote:Does it seem plausible at all that it could be picking up some new electrical interference if it was moved slightly?

It seems fairly unlikely. What I would guess might be more likely is disturbing an intermittent/partial contact in the windvane signal connectors or cabling.

Quote:am I correct that a fluxgate compass issue would have nothing to do with the AWA reading or TWA calculation?

Correct. Heading is used in Ground Wind calculations, but not true or apparent (there's some background on this here.) Do you already have an open question about the heading fault diagnosis? I am sure we can help with that one.

Quote:both boat speed and wind speed/angle were an issue after the software upgrade do you think this is pointing more towards an iTC-5 problem as compared to the transducers themselves? Any troubleshooting steps I should consider there?

If problems are resolved by recalibration then they're probably not caused by hardware faults, unless - in this instance - you had a developing problem with the ITC5's non-volatile memory storing the calibration values. This is something to keep an eye on until you gain confidence that the new values are retained for an extended period, but not something I would be concerned about now. Very occcasionally some product calibration/setup values can become reset (we saw this sometimes on older autopilots, for example) to default values as a result of - I believe - an unfortunate and coincidental power-cycle/reboot just at the time when the product was writing to its memory. In this rare circumstance then you could end up with an incomplete write and corrupted information, which the product would detect and reset to its defaults as a precaution. An ITC5 would be rebooted during a software upgrade: it's conceivable this reboot happened at just the wrong moment.

Regards,
Tom

[tmass60]

Thanks Tom for your reply. I agree that new electrical noise seems unlikely and I don't recall any power recycling or odd events during the software upgrade so odds are the iTC-5 is OK as well.

On the wind speed readings:
Based on your input I am starting to lean towards a masthead transducer issue. This last weekend I noticed mine was clearly spinning slower than a neighboring sailboat. I have no way of knowing of course if the other boat was calibrated correctly, but the difference in spin rate and the fact the other boat read 2-3 knots greater consistently seems like a good data point. I also now recall that last year I was seeing some odd true wind calcs at low wind speeds which to me anyway would seem to point to maybe some sort of resistance in the rotation of the transducer that is more overcome with higher wind speeds.

I did put my multi-meter on the connections at the base of the mast per https://forum.raymarine.com/showthread.php?tid=97. 7.9 volts on red. Blue and green were slightly different - from recollection 4.6V and 5.2V - somewhat steady but the wind was steady direction as well so maybe that makes sense. Yellow was 1.8V but not sure this helps all that much if I have a masthead rotation issue seeing this voltage increases/decreases with speed.

I ordered a new masthead transducer and will let you know what I discover once installed. Based on the attached picture can you tell me if this is an "old" or "new" style connector? I read somewhere in the forum there is an o-ring on the old that needs to be removed but was unclear if it somehow had to be re-installed?

Seem like I am on the right track for the wind speed issue?

On the fluxgate compass heading issue:
I have not posted anything about this but found https://forum.raymarine.com/showthread.php?tid=96. I purchased a replacement M81190 and will test both old and new. (I seem to recall I tested the current one last year when the problem initially appeared but have to admit I thought "screen to blue" was a typo and tested "green to blue" so my results didn't make sense.) The problem is much more consistent now compared to last year so we'll see. It is "screen" or the "non-insulated wire" to blue correct?

Thanks again,

Tony

[Tom - Raymarine - Moderator]

Hello Tony,

Yes, the only way to be sure that the wind speed data from the masthead is really correct is to look at the signals on an oscilloscope and count the frequency of the pulses - which is what our service workshop would do - but if the cups speed to be spinning visibly slower than an adjoining boat then I don't think you need to go to that level: your windvane's bearings are probably not as free as they used to be. This was a common problem on the old-style windvanes and was one of the key improvements in the current design.

Quote:Based on the attached picture can you tell me if this is an "old" or "new" style connector? I read somewhere in the forum there is an o-ring on the old that needs to be removed but was unclear if it somehow had to be re-installed?

This is the old-style connector. To use a new windvane on the old base, you should indeed remove the O-ring from the seat of the socket of the old base. This is not replaced or re-used: the new windvane seals with an O-ring around the windvane's shaft, which compressed against the outside of the windvane's male connector assembly by its captive locking ferrule, rather than in the mounting socket.

On the fluxgate, yes, by 'screen' we mean the bare, non-insulated wire. Sorry the terminology wasn't clear.

Regards,
Tom

[tmass60]

Thanks Tom. I hope to have the new wind transducer installed soon. Seems highly likely though that will resolve the issue.

I have some further info. on the fluxgate compass problem mentioned briefly below. Will start a new thread that maybe you can pick-up seeing it is a different topic.

Thanks again,

Tony