Getting GPS position data from SeaTalk1 to NMEA 0183 via SeaTalkNG SPX-30

[nixxon]

Baggywrinkle, nixxon, what software are you using to produce those diagrams of your installations? They're very neat and well labelled.

The illustrations I use are mostly copy and paste from existing illustrations. I use Microsoft Paint for the modest editing.
I copy product illustrations from the relevant product manuals (Selecting the area to copy by pressing Windows key +Shift+S). Then I paste the selection into Microsoft Paint. There I trim and arrange the illustrations before adding simple lines and text. This no-cost method works pretty well on any computer.

 

[cpedw]

Thank you for pointing out that "The 'Power and data cable' and the 'Multi-cable' are one and the same cable, not two different cables. All of the NMEA and Seatalk wires are in his one cable." Awesome! Now we talk
I got fooled by the different descriptions of the same cable in the E-series Installation Instructions ...

I get very annoyed (it's an age thing I think) by technical documents that use different terms to describe a single item. It happens a lot in my experience and when I'm working beyond my knowledge and experience, it makes life unnecessarily complicated.

Derek

 

[Baggywrinkle]

Baggywrinkle, nixxon, what software are you using to produce those diagrams of your installations? They're very neat and well labelled.

I'm ashamed to say, Powerpoint - simply because I have it.

Windows snipping tool to copy photos or diagrams from the web, and the rest in Powerpoint.

I use small filled circles as terminals because they have 8 points which the connectors (lines) snap to - I can force powerpoints line routing algorithm to produce the line I want by choosing the point I connect it to on the circle - then adjust by dragging the lines to their final position - means you can shove components around the diagram and they all remain connected - then just tidy up the lines until the layout is clean and satisfactory.

I'd be lying if I said it was easy and didn't take much time to produce - but you get faster with practice.

Did one for my charging system too ...

 

[prv]

Baggywrinkle, nixxon, what software are you using to produce those diagrams of your installations? They're very neat and well labelled.

I think Nixxon's one is cleverly copy-pasted together from Raymarine manuals.

For what it's worth, I use Omnigraffle for mine.

Pete

 

[nixxon]

After evaluating all your great advice I lean towards installing a separate (shielded, below deck) NMEA-0183 GPS antenna for the VHF radio. This would be a very clean install that seems less likely to fail if there should arise a bad situation affecting external components like the chart plotter in the cockpit or the external GPS mushroom fitted onto the pushpit. If either of these components fail, or if any cable or connector fail, the VHF DSC distress call will also fail.

Nevertheless I will have to try out the ST1 output from the SPX-30 --> E85001 (NMEA 0183) --> VHF. Then I will know if the SPX-30 relays STNG data to the ST1 bus.

If I manage to pull the cable through the boat, I will also try connecting the E90W directly to the VHF. I think a CAT6 internet cable may be suitable.

 

[PaulRainbow]

After evaluating all your great advice I lean towards installing a separate (shielded, below deck) NMEA-0183 GPS antenna for the VHF radio. This would be a very clean install that seems less likely to fail if there should arise a bad situation affecting external components like the chart plotter in the cockpit or the external GPS mushroom fitted onto the pushpit. If either of these components fail, or if any cable or connector fail, the VHF DSC distress call will also fail.

Nevertheless I will have to try out the ST1 output from the SPX-30 --> E85001 (NMEA 0183) --> VHF. Then I will know if the SPX-30 relays STNG data to the ST1 bus.

If I manage to pull the cable through the boat, I will also try connecting the E90W directly to the VHF. I think a CAT6 internet cable may be suitable.

It will if it is stranded cable. But don't waste time pulling cables through just to see if it will work, it absolutely will.

 

[pvb]

If I manage to pull the cable through the boat, I will also try connecting the E90W directly to the VHF. I think a CAT6 internet cable may be suitable.

Wouldn't a twisted pair work?

 

[Baggywrinkle]

I used automotive trailer cable into sealed junction boxes. No shielding, no twisted pairs, the data rate and voltage levels for NMEA0183 means that all the issues with high frequency (high data rate) transmission don't even register, and it is practically immune to electromagnetic interference. ...... you could send RS232/RS432 - which is NMEA0183 over a doorbell cable and it would be fine.

High frequency used by gigabit ethernet or similar use much reduced voltage levels and much higher frequencies, so shielding and twisted pair makes sense due to electromagnetic compatibility issues, but for RS232/432 it really is not the case.

At 4800 baud, RS232 cable length can be 30m

 

[Birdseye]

Hello

We are sailing a 2010 Jeanneau Sun Odyssey 45 DS that we bought this year. The VHF radio (Standard Horizon GX1600) is not connected to an NMEA 0183 source. Thus it sounds an GPS-fix error alarm a couple of times every time it is powered on. And the DSC distress alert does of course not work as intended.

I need to serve the VHF some position data over NMEA 0183 of type RMC, GLL or GGA .

All the equipment on board is from Raymarine communicating via the SeaTalk1 (ST1) or SeaTalkNG (STNG) protocol. The Chart Plotter is an E90W connected to an external Raystar 125 (or similar) GPS antenna (ST1). The E90W communicates with the SPX-30 course computer via STNG.

I have a E85001 ST1-NMEA interface box that can grab ST1 position data and output GGA (and GLL) on the NMEA out pins.

Now the question is if the ST1 ports on the SPX-30 retransmits the position data it may receive from the E90W. Does anyone know if that is the case?

I have made a drawing of the setup I have planned:

NixxonView attachment 98042

Cant answer your question but thats an impressive schematic of what you intend. How did you do it? What software did you use?

P.S. For myself I would be inclined to buy another GPS aerial and connect that to the radio wince that would also give some redundancy. You can get GPS antennae quite cheaply - I use one that I got from ebay since my B&G plotter has an internal aerial which isnt as good as I would like.

 

[nixxon]

Cant answer your question but thats an impressive schematic of what you intend. How did you do it? What software did you use?

P.S. For myself I would be inclined to buy another GPS aerial and connect that to the radio wince that would also give some redundancy. You can get GPS antennae quite cheaply - I use one that I got from ebay since my B&G plotter has an internal aerial which isnt as good as I would like.

You made a pretty good summary of this thread in your post there

 

[PaulRainbow]

Wouldn't a twisted pair work?

That was my first thought, but then i thought, if he used stranded ethernet cable there would (of course) be 6 spare wires, if the Raymarine GPS failed he could use one of the spare pairs to send GPS data from the new GPS receiver.

 

[nixxon]

You absolutely can connect the E90W to the VHF directly using NMEA.

Just a short update. I solved it for now by connecting a multi stranded CAT5 Ethernet wire directly between the E90W and the VHF. It took me more than 3 hours to crimp dupont style connectors, route the cable down from the NavPod, through the MFD stand pipes, into the ceiling of the aft cabin, back into the hidden compartement where the steering wires are located and so on. I now see position data on the VHF screen and the annoying missing-position-data-alarm has gone away

As a bonus I now have 3 spare twisted pair wires that may be put into use if I need to do so.

When I one day get an AIS transceiver, possibly an AIS 650 or 700, I count on that the position data from the AIS transceiver (with a separate GPS antenna) is transmitted in a less exposed way via the NMEA 0183 output.

Thank you all for all the tips and supporting information