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old-sailer 05-05-2012 06:12 PM

Seatalk help needed badly
 
Go-hifreann-leat

sea_hunter 05-05-2012 08:23 PM

2000 is backwards compatible as NMEA is NMEA. You'll need the splice bidata cable kit though that you can get through a chandler.

Faster 05-05-2012 09:14 PM

Re: Seatalk help needed badly
 
Seatalk, however, isn't NMEA, it's proprietary to Raymarine. Our ST40 era remote is 'talking' to our ST60 autohelm over the Seatalk route. I would think that on the Seatalk link you should be OK.

Raymarine should be able to tell you what's what, but I'd look closely at the wiring first.

brak 05-05-2012 10:23 PM

Re: Seatalk help needed badly
 
You need more than speed to get a true wind value calculated (even assuming that their wind instrument can calculate it).

At a *very* least you need speed through water and heading, in addition to apparent wind. Depending on modes of calculation available from Raymarine wind instrument, you may also/instead need SOG/COG. In any case there must be at least some source of vessel speed and "direction".

Check with Raymarine for specifics or read documentation of your wind instrument, it will likely say what information it needs.

PorFin 05-05-2012 11:26 PM

Re: Seatalk help needed badly
 
I think Brak's on the right track. Without heading info, there's a missing part of the equation for the true & apparent wind calculations.

I think you'll need to get some GPS data fed into the mix...

PorFin 05-06-2012 10:53 AM

Re: Seatalk help needed badly
 
Quote:

Originally Posted by old-sailer (Post 867846)
Lets not get off track, this has nothing to do with my question.

However:
GPS data has nothing to do with true to apparent wind. You need (1) the wind speed, (2) the wind direction relative to the craft, (3) the speed of the craft. The ST40 knows the direction of the wind and the speed of the wind and that's all that is required for true wind. It then needs the craft speed. Then it calculates baed on the formula.

Yeah, you're right -- apologies humbly rendered... :o

overbored 05-06-2012 12:33 PM

Re: Seatalk help needed badly
 
Quote:

Originally Posted by old-sailer (Post 867848)
I can get them all running if I do the ST40 on it's own but then I only get true wind. No apparent.

if you are not moving you will get true wind. if you are moving you will be getting apparent wind

Classic30 05-06-2012 10:58 PM

Re: Seatalk help needed badly
 
Quote:

Originally Posted by old-sailer (Post 867635)
Can I pick your collective brains??

I have an elderly Autohelm depth unit (now owned by Raymarine) AND a Raymarine speed log, they talk via Seatalk cable. No problem there.

I purchased a Raymarine ST40 wind, a Seatalk junction box and a 15 ft cable to connect them all together, BUT the older units will not talk to the new ST40 wind.

O-S, just so you don't think you're asking a stupid question, if you've got the ST40 Depth working with your Autohelm, I can't see any reason why the new unit shouldn't work too - although Raymarine have been known to come up with you-beaut firmware revisions and not test for backwards compatibility.

Assuming you've followed the Manual and all your Seatalk connections are tight: If you change the backlight level on the Wind unit, does it change on the Depth display also - and vice-versa??

(Might seem like an obscure thing to ask, but that's how you check that data is being passed between Raymarine instruments)

brak 05-07-2012 12:34 AM

Re: Seatalk help needed badly
 
heading or course are required to calculate true wind. you are welcome to read the following for details: PolarCOM “True” Wind Calculation Polar Navy Co
also this: Re: True "true wind" & the Raymarine ST60, or other

Classic30 05-07-2012 01:52 AM

Re: Seatalk help needed badly
 
Quote:

Originally Posted by brak (Post 868088)
heading or course are required to calculate true wind. you are welcome to read the following for details: PolarCOM “True” Wind Calculation Polar Navy Co
also this: Re: True "true wind" & the Raymarine ST60, or other

Hmm... Lots of factual information there. :rolleyes:

O-S is quite correct in what he's asking for - true wind display as opposed to apparent - relative to the direction of the boat. ...but then we knew that, didn't we, kiddies?? :D


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