Seatalk and NMEA driving me nuts

Yeoman_24

Yeoman_24

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Ok. Two questions within this post.

Firstly, my newly bought boat (late 1970's) has, I believe, a Seatalk/ng back bone. Attached are a Garmin GPS820 plotter, Garmin radar, Raymarine AIS, autopilot, transducer, and tri-data gauge. I have just bought a NASA Clipper wireless wind instrument. Can I plug the NASA receiver display straight into the backbone and if I can, what lead do I need?

Secondly, can anyone point me in the direction of an 'all in one', idiots guide as to how the different versions of Seatalk and NMEA can link in and practically how you do it. I'm pretty good with IT and technical stuff in general but new to this marine lark so need some pointers please.
 
Seatalk ng is basically N2K just with a different connector on the end of the wires. You can buy adaptors or just cut and splice the cables yourself.
 
Keith-i said:
Seatalk ng is basically N2K just with a different connector on the end of the wires. You can buy adaptors or just cut and splice the cables yourself.
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Not true, I'm afraid. The Nasa Clipper wireless wind is NMEA0183 only, and isn't compatible with NMEA2000. However, the Garmin GPS820 plotter has NMEA0183 inputs, so you might try wiring it in to that. Whether the data will be transmitted on to the SeaTalk network is questionable.
 
The Raymarine site has a fair amount of information on how to use 0183 in STng backbones. You will need a converter if you want the information to be available to all devices. However, you may already have a device or two that takes both STng/NMEA2000 and 0183 (eg the plotter). Whilst it probably wont repeat the data round the system, it will use it (and output back to the NASA if this is of any use).
 
Yeoman_24 said:
Firstly, my newly bought boat (late 1970's) has, I believe, a Seatalk/ng back bone.
Click to expand...

Despite pvb's denials, Seatalk ng is really just N2K with different connectors. However, are you sure it is an STng backbone? That would make the electronics fit out quite recent. There are older versions of Seatalk that are related to STng only in name.

Easy to spot. STng cables are mainly blue and spur cables are white. Easier to show pictures than describe them - they are easy to recognise when you know them:

http://www.raymarine.com/view/?id=5536
https://hudsonmarine.co.uk/index.php?module_display=41&pid=151566
https://hudsonmarine.co.uk/index.php?module_display=41&pid=141883
 
lpdsn said:
Despite pvb's denials, Seatalk ng is really just N2K with different connectors.
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You've misinterpreted my post. The OP asked about connecting a Clipper wireless wind sensor to his SeaTalk ng network, and Keith-i replied that he could just tag it in with adaptors or cables. I said that wasn't true, because the Clipper sensor only outputs NMEA0183.
 
pvb said:
You've misinterpreted my post. The OP asked about connecting a Clipper wireless wind sensor to his SeaTalk ng network, and Keith-i replied that he could just tag it in with adaptors or cables. I said that wasn't true, because the Clipper sensor only outputs NMEA0183.
Click to expand...

In that case I apologise.
 
Yeoman_24 said:
Can I plug the NASA receiver display straight into the backbone and if I can, what lead do I need?
Click to expand...

You need something to convert NMEA0183 sentences into N2K PGNs.

Actisense sell a gateway that is probably suitable for your needs. You'd need to check that it converts the sentences you have from the NASA wind sensor into PGNs that are usuable by what you have on the STng network. You'd also need a cable that will allow you to connect DeviceNet (N2K standard) to STng.

http://www.actisense.com/products/nmea-2000/ngw-1/downloads-ngw1

There's also a similar box from AMEC.

ShipModul also do various multiplexers that would do the job (you'd need to make sure that it has an N2K port).

I have both an Actisense NGW-1 and a ShipModul MiniPlex-3USB-N2K. I bought the NGW-1 first but if doing it again I'd skip that and just buy the ShipModul box, which allows you to interface multiple NMEA0183 devices to N2K rather than just one. In fact, one day I might remove the NGW-1 and sell it as I could configure the ShipModul box to do the job it is currently doing.

Yeoman_24 said:
Secondly, can anyone point me in the direction of an 'all in one', idiots guide as to how the different versions of Seatalk and NMEA can link in and practically how you do it. I'm pretty good with IT and technical stuff in general but new to this marine lark so need some pointers please.
Click to expand...

You should be able to get all the info you want on NMEA0183 with a web search. Surprisingly, www.nmea.org have a fair amount of free information on N2K on their web site (rather un-nmea-like). N2K is a variant of the SAE J1939 standards - i.e. CANbus on cars. It uses DeviceNet as the physical layer - except for Raymarine kit which has alternative connectors.
 
There was a suggestion earlier in the thread to connect the NASA unit to the Garmin NMEA0183 ports. There's a good chance that the wind info will be propagated on to NMEA2000/STng. Obviously this depends on one of the ports being available (might be being used for AIS/VHF).

You may also be able to use the autopilot, especially if you want to use it to sail to wind. That will depend on what model. You may find that some Raymarine autopilots understand a different NMEA0183 wind sentence to the one that the NASA one uses. Before the howls of derision cut in, it's been Raymarine units that have used a deprecated sentence rather than NASA who use the latest one.
 
The owners manuals tell you what NMEA sentences they support.

The Garmin GPSMAP 820 supports receiving wind sentences MWD & MWV over 0183 and transmits Wind data 130306 over 2000 PGN - you just need to confirm whether this is supported by Raymarine SeaTalkng.
 
DrSpock said:
The owners manuals tell you what NMEA sentences they support.

The Garmin GPSMAP 820 supports receiving wind sentences MWD & MWV over 0183 and transmits Wind data 130306 over 2000 PGN - you just need to confirm whether this is supported by Raymarine SeaTalkng.
Click to expand...

Does the manual actually say that incoming NMEA0183 sentences are converted and transmitted as NMEA2000?
 
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