Smartcraft , NMEA, SETALK and etc.

[searaypuget]

I am new to the boating world but quite familiar with networking technologies in general. It is pretty fascinating to see how all different components are talking to each other although I wish they all talk in a common language. Based on what I read, Smartcraft has its own protocol and can talk to other devices on NMEA thru SC-NMEA gateway which all makes sense. Then, I was reading thru this installation instruction to understand how a SC gauge is connected, I see it also connects to NMEA protocol. I thought SC requires a gateway to talk to NMEA. What am I missing here?
I am not trying to install the gauge but just trying to understand how it all works together if I want to share data across different protocols.

 

[nduck88]

I would guess that is a NMEA 0183 GPS input into the Smartcraft system so that it can calculate SOG. You do need a gateway to connect to NMEA 2000 and get engine data, fuel consumption, etc out of Smartcraft and onto a NMEA 2000 network. Not an expert and currently trying to navigate the best way to add a gateway to 2002 5.0 MPI which are smartcraft capable but came from the factory with analog wiring harnesses. I hope you were out last weekend, I just moved to north of LA from Seattle a few months ago and heard it was awesome out. Wishing I left the boat up there for the summer now.

 

[searaypuget]

Yes I was out on Lake Washington last weekend and it was nice indeed.
I understand that I need a gateway to translate between SC and NMEA. What confuses me is how NMEA GPS inputs to SC1000 gauge. I believe SC is essentially CANBUS which isn't compatible with NMEA directly. Perhaps, SC1000 can take inputs from NMEA as well.

I would guess that is a NMEA 0183 GPS input into the Smartcraft system so that it can calculate SOG. You do need a gateway to connect to NMEA 2000 and get engine data, fuel consumption, etc out of Smartcraft and onto a NMEA 2000 network. Not an expert and currently trying to navigate the best way to add a gateway to 2002 5.0 MPI which are smartcraft capable but came from the factory with analog wiring harnesses. I hope you were out last weekend, I just moved to north of LA from Seattle a few months ago and heard it was awesome out. Wishing I left the boat up there for the summer now.

 

[Skybolt]

So here is what you are missing. ...

Smartcraft uses an engine protocol called J1939, essentially NMEA 2000 with different message content, although some are the same.

A little background. CAN bus (Controller Area Network) is basically RS485, a hardware spec. NMEA 2000, J1939, Seatalk NG are all protocols that run on top of that hardware. All use very similar messages, PGN's. The content of the PGN's differ slightly and vastly all at the same time, depending on the PGN. Google J1939 and NMEA 2000. There is a lot of info out there.

 

[sfergson727]

There should be a blue and white wire in the display harness, which is the input for the NMEA data, at least from what I can remember when I installed it. (a long, long time ago)