Hoping to understand Raymarine ST60 and ST60+ Tridata instrumentation.

[RichardS]

As I slowly get my boat electronics working the way I want, I'm now looking at the things that it doesn't seem to do. I probably should have started with this but these things are not critical so haven't affected my enjoyment of the boat.

I have a C80 Classic plotter, ST60 Wind Instrument and ST60+ Tridata speed and depth display. All the speed data comes from the GPS as I have no speed paddle through-hull on this boat.

The first thing which puzzled me was that the wind instrument has a button for Apparent Wind or True Wind ..... but True Wind doesn't work. Having read this forum and others over the years, I know that the ST60 will only make the True Wind calculation from paddle wheel speed and not from GPS speed so I can forget about that.

The second issue is that the Tridata instrument has a display for Log and a button for Trip. I understand that Log is supposed to show the total distance travelled by the boat since she was launched whereas the Trip is supposed to give me the distance travelled since the instrument was last switched on. Once again, both Log and Trip are always zero.

My first thought is that this is the same issue as True Wind and that Log and Trip can only receive data from the missing paddle wheel. However, this sounds a bit illogical since the best source of distance travelled would surely be the GPS data which gives actual distance travelled over the ground rather then the paddle wheel which could be whizzing around even if you were sitting in the marina.

Is there a way to get the Log and Trip (particularly the latter) to accept data from the GPS?

Richard

 

[prv]

Not as far as I know - the ST60 system's definition of distance travelled is "by the log". The lifetime distance count lives in the log display head; mine has just shrunk by thousands of miles since I replaced the display

Pete

 

[Colvic Watson]

It's all log only and dates back to when Seatalk1 came along and GPS was a new fangled gizmo. I have no idea why it hasn't been updated, except that the units would have to be designed to interpret the GPS feed from NMEA. Even so, my brand new Raymarine wind instrument will only do true wind from the log, so still not updated! But that said, Seatalk1 is a dream system, so incredibly easy to set up and manage.

 

[RichardS]

Even so, my brand new Raymarine wind instrument will only do true wind from the log, so still not updated!

I'm amazed by that CW. I also would have expected Raymarine to have sorted out this historical anomaly.

What about the Log and Trip functions? It seems to me that GPS is a better source for that data so have Raymarine at least sorted that out?

Richard

 

[Colvic Watson]

I'm amazed by that CW. I also would have expected Raymarine to have sorted out this historical anomaly.

What about the Log and Trip functions? It seems to me that GPS is a better source for that data so have Raymarine at least sorted that out?

Richard

I don't know, the log and trip aren't things I use, GPS is way better - except I sometimes compare the trip to the GPS to see how brilliant or not as was at tide planning

The i40 units are good value, small and straightforward to use and easy to read. I trust Seatalk1 for its simple functionality and I wouldn't get on with an instrument MFD, my eye natural drops to the instrument I want the data from. The innards were probably designed 20 years ago and just rehoused, there's no money for R&D in budget boat instruments!!!

 

[FWB]

... I trust Seatalk1 for its simple functionality and I wouldn't get on with an instrument MFD, my eye natural drops to the instrument I want the data from. The innards were probably designed 20 years ago and just rehoused, there's no money for R&D in budget boat instruments!!!

The i70 MFD is very good and can be used as a repeater on the Seatalk 1 network, without the need for the NG system.

 

[Pye_End]

What about the Log and Trip functions? It seems to me that GPS is a better source for that data so have Raymarine at least sorted that out?

Richard

Log distances on these instruments are there to allow navigators to dead reckon. GPS will probably have its own log functions, so if you wish to use logged distance over the ground then presumably you will be able to do so.

If GPS becomes unavailable for any reason, or you wish to re-sharpen your traditional navigation skills, then 'through the water' information is what you will need.

 

[RobF]

It's all log only and dates back to when Seatalk1 came along and GPS was a new fangled gizmo. I have no idea why it hasn't been updated, except that the units would have to be designed to interpret the GPS feed from NMEA. Even so, my brand new Raymarine wind instrument will only do true wind from the log, so still not updated! But that said, Seatalk1 is a dream system, so incredibly easy to set up and manage.

Agree about the simplicity of SeaTalk1, I just wish it was easier to interface with NMEA 0183. To date, the only options I've found are a Tridata Graphic (which are very hard to find) or a ShipModul multiplexer.

 

[nigelmercier]

I built a device to take a GPS feed and simulate a paddle wheel. It works well, although it seems that TriData units do not all produce the same result in factory defaults, so I've added a calibrate mode that sends the correct frequency for 5 knots. I can supply details of the PCB and software.

 

[prv]

Agree about the simplicity of SeaTalk1, I just wish it was easier to interface with NMEA 0183. To date, the only options I've found are a Tridata Graphic (which are very hard to find) or a ShipModul multiplexer.

Raymarine do (or did?) their own interface box. I inherited one on Ariam.

Pete

 

[Colvic Watson]

You can feed NMEA into the Seatalk bus via an ST60 or SPX30 autopilot.

 

[RichardS]

I built a device to take a GPS feed and simulate a paddle wheel. It works well, although it seems that TriData units do not all produce the same result in factory defaults, so I've added a calibrate mode that sends the correct frequency for 5 knots. I can supply details of the PCB and software.

Thanks Nigel. I know we've talked about this a few years ago but now I've retired I'm finally getting around to "tweaking" the things on the boat which have always been well down the to-do list ...... and so, yes, I would be very interested in your home-built solution as it's not something I would want to spend serious money on (there are some commercial products available I believe?)

Is it possible to input GPS and simulated-paddlewheel into the Raymarine system at the same time so that the ST60 Wind and the ST60+ TriData can use "paddlewheel" and therefore show True Wind and Log/Trip whilst the C80 will still display GPS true SOG ..... or is this not necessary because the paddlewheel is also true SOG (no current here) but just in a different format?

Either way, I'll PM you with my email address.

Many thanks

Richard

 

[nigelmercier]

Is it possible to input GPS and simulated-paddlewheel into the Raymarine system at the same time so that the ST60 Wind and the ST60+ TriData can use "paddlewheel" and therefore show True Wind and Log/Trip whilst the C80 will still display GPS true SOG ..... or is this not necessary because the paddlewheel is also true SOG (no current here) but just in a different format?

The ST60 system thinks it is getting a feed of a paddlewheel, so wind and log are updated as expected.

I think I have a working spare, but if more people wanted one I could get some more boards produced.

 

[sailaboutvic]

Ok I lost .
Why would the paddle wheel ( I take it your talking about the log paddle wheel ) effect the true and app wind speed ? .

 

[RichardS]

Ok I lost .
Why would the paddle wheel ( I take it your talking about the log paddle wheel ) effect the true and app wind speed ? .

As far as I understand it Vic, the apparent wind as felt actually on board is always forward of the true wind and, if the wind is from ahead, greater than the true wind.

What the True Wind calculator does in the Raymarine electonics is take the forward speed of the boat from the log paddle-wheel and "deduct" or "add" this from the apparent wind to give you the strength and the wind direction of the True Wind.

So far so good ..... but this raises the question of why the Raymarine can't do the same calculation using the forward speed and course from the GPS rather than the paddle-wheel.

There are explanations of this on the web involving concepts such as True Wind, Apparent Wind, Ground Wind and Actual Wind but it's all gibberish to me! :ambivalence:

Richard

 

[sailaboutvic]

As far as I understand it Vic, the apparent wind as felt actually on board is always forward of the true wind and, if the wind is from ahead, greater than the true wind.

What the True Wind calculator does in the Raymarine electonics is take the forward speed of the boat from the log paddle-wheel and "deduct" or "add" this from the apparent wind to give you the strength and the wind direction of the True Wind.

So far so good ..... but this raises the question of why the Raymarine can't do the same calculation using the forward speed and course from the GPS rather than the paddle-wheel.

There are explanations of this on the web involving concepts such as True Wind, Apparent Wind, Ground Wind and Actual Wind but it's all gibberish to me! :ambivalence:

Richard

Ok it make sense now , it's using the info the paddle wheel given to cal the diffances between the app and true , I haven't looked at it that way .
Althought the GPS will give SOG so why not take it from there , Mmmmm now I know why I can't get true wind on my display , my log not been in for some year as I got fed up taken it out to clean it every few days. .
if it help Richard ,

 

[prv]

this raises the question of why the Raymarine can't do the same calculation using the forward speed and course from the GPS rather than the paddle-wheel.

They could, of course, and I believe (but could be mistaken) that their current kit has the option to do so (and then they call the result "ground wind" just to avoid ambiguity). But sadly in the ST60 era they were still fixated on the idea that true wind = apparent wind - log speed. No log speed, no true wind.

Pete

(It's a rhetorical calculation.)

 

[nigelmercier]

... this raises the question of why the Raymarine can't do the same calculation using the forward speed and course from the GPS rather than the paddle-wheel.

Because the ST60 Wind takes data from the SeaTalk bus, if this does not contain speed data then the calculation cannot be done. Incidentally it only needs the speed (not the course), this vector is then used with the wind vector.

 

[prv]

Because the ST60 Wind takes data from the SeaTalk bus, if this does not contain speed data then the calculation cannot be done. Incidentally it only needs the speed (not the course), this vector is then used with the wind vector.

But it must be a very rare ST1 bus that doesn't have SOG data on it. They just decided not to (or didn't think to) allow its use for wind calculations.

Pete

 

[RichardS]

Because the ST60 Wind takes data from the SeaTalk bus, if this does not contain speed data then the calculation cannot be done. Incidentally it only needs the speed (not the course), this vector is then used with the wind vector.

As Pete says, I'm sure that my RS125 mushroom inputs its data into the Seatalk bus as the NMEA port on the back of my C80 was only used to output position to the DSC VHF. The NMEA input wires were just left disconnected until I commandeered the NMEA port for AIS use a few weeks ago.

Does this mean that your paddle-wheel simulator thing won't work on my system Nigel?

(the Seatalk 2 port on my C80 is also not used for anything if that is relevant)

Richard