SeaTalk NG (New Generation)

[Manlio]

Presented by Raymarine in 2007, I am unable to find around a white
paper or some clear and complete presentation of this protocol.
Someone may give me an hint ?
Thanks
Manlio

 

[Meindert Sprang]

Presented by Raymarine in 2007, I am unable to find around a white
paper or some clear and complete presentation of this protocol.
Someone may give me an hint ?

As Seatalk has always a proprietary and thus closed protocol, I don't see
them publish any info on Seatalk NG....

Meindert

 

[TomS]

Isn't it just NMEA 2000 with different connectors?

Yes, Seatalk NG is NMEA2000. Using their own connectors. There are

 

[TomS]

Isn't it just NMEA 2000 with different connectors?

Yes, Seatalk NG is NMEA2000. Using their own connectors. There are adapters
cables available that
converts ST NG connectors to DeviceNet micro-C connector (standard NMEA 2000
connector).

TomS

 

[Meindert Sprang]

If you do a google search on this news group, you'll see that I provided a
link to a document that describes the protocol for normal SeaTalk. The
author was very responsive in some questions that I had.

Yep. http://www.thomasknauf.de/seatalk.htm

While I can't tell you if there are differences between normal SeaTalk and
SeaTalk NG, I would bet that they are the same and that main differences
are in the physical and datalink layers.

It is indeed very different, NG is based on NMEA2000.

IMHO, RayMarine has too much invested in lots of software to be making
fundamental changes in the protocol.

Well, since NMEA2000 is based on CAN, it is relatively easy to run NMEA2000
alongside some proprietary protocol on the same CAN bus and call is Seatalk
NG.

Meindert

 

[Meindert Sprang]

Quoting from a RayMarine web site, "SeaTalk NG is an NMEA 2000 compatible
system, which can be interconnected to NMEA 2000 networks with an adapter
cable. It can also be interconnected to SeaTalk and SeaTalk2 networks for
backwards compatability with existing Raymarine installations."

They only tell you half the truth... Seatalk and Seatalk NG/aka NMEA2000 can
be interconnected, but there is a small interface box/cable involved which
does the translation between both physical layers AND low level protocol.
The actual content of the datagrams might still be the same, which makes
sense.

NMEA2000 is invented by NMEA and is an application layer on top of CAN,
which is competely different from SeaTalk. Seatalk NG could be the same
type of datagrams used in Seatalk, but stuffed into CAN frames and sent on a
CAN network. There are a few similarities between Seatalk and CAN, like the
short datagrams, collision detection and the connectionless protocol, it is
merely publishing data on a network.

Meindert

 

[Manlio]

Followup to msg on Wed, 5 Mar 2008 09:26:30 -0500, "Bill Kearney"
<[email protected]> :
(Original msg on bottom)

I see ... that's why I have see some drawing where the net is tapped (
I mean terminated) like the ethernet PC net.

For NMEA 2000 I found as a good doc:

http://www.jackrabbitmarine.com/files/NMEA2K_Network_Design_v2.pdf

Thanks
Manlio