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Garmin 740 to Raymarine SPX30

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I connected the SPX30 to the Garmin 740 via SeatalkNG/N2k last weekend. I also have on the network a depth/speed sensor, wind sensor, and garmin's small GMI10 display.

From the 740 and the GMI, I can see all devices on the N2K network, including the SPX30. Boat speed, wind speed, XTE, its all there. I can even map the compass heading from the SPX30 to my 740 display. Sweet.

However, the SPX will not see anything from the 740 or any other network device. No distance to waypoint, no bearing to waypoint, no wind data, depth, etc.

Any ideas as to what's going on? The data appears to be broadcast out, but the SPX is not listening. Let me know what you think.

25 Replies

  • How can you tell what the SPX30 course computer sees, Pete? I'm guessing you mean the control head, but am not sure which you have, or how it's hooked up?

  • Sorry, I should have added that. The control head is an ST6002 connected via Seatalk. When I try to go into Track mode, I get error "data not available" (That's from my memory, but it was a message similar to that). Scrolling through display shows dashed lines for DTW, BTW, XTE, etc.

  • Peter, I think the problem is that the SPX30 isn't converting the STng/N2K data to SeaTalk. I recall a similar issue that my local yard Wayfarer puzzled over for some time. I think it took an NMEA 0183 work around but I do know the boat can now use Garmin MFD go-to points with an ST7002 head and SPX30. It's possible that Raymarine's new STng-to-SeaTalk converter could take some pain out this. Have you talked to Raymarine technical support?

  • Thanks for the response. I have spoken with Raymarine. Unfortunately not a lot of support - other than "don't do it". What you mentioned is the path that I'm trying next.

    I'm looking at the Actisense NGW-1. Once communicating, my concern is if the comm link will be fast enough to allow the autopilot to be controlled by Apparent Wind Angle. Any thoughts?

  • I have a 750 (same as 740 but different charts) talking to an SPC30 with no problems. My installation uses an ST70 ap controller rather than your ST6002.

    The Garmin outputs all route data just fine with the following restriction: The only time I can see route waypoints from the Garmin on the autopilot is if I create a route manually using "Route to" on the Garmin. If I ask the Garmin to goto a waypoint then no data appears at the SPX - if I create a route with a single waypoint on the Garmin (or more than 1 waypoint) it appears and works fine.

    I suspect that the problem has to do with Waypoint naming restrictions that the Raymarine enforces. If I try to Navigate to a waypoint rather than a single waypoint route I believe that the 750 outputs the waypoint ID without a name that the SPX can understand. (I think). I've learned to live with it. Creating a single waypoint route is about 2 more keystrokes than navigating to a waypoint.

  • Slightly off topic (apologies for minor thread hijack)...

    The thing that irritates me about the Garmin / ST70 / SPX integration is that I have no way to update the instrument or Autopilot firmware. As far as I know Raymarine provides just one way to update their ancillary hardware - that being via a Raymarine chartplotter.

  • How exactly did you hook up the ST70 AP Controller and the SPX30 to the Garmen network?

  • All that I did was get a Raymarine SeaTalkNG to NMEA2000 adapter cable and plug it into a Seatalk-NG T fitting on one end and into the Garmin on the other. Works just fine.

  • So I assemble the Raymarine Seatalk ng backbone with the ST70 and the SPX30 connected to it then install a normal Raymarine Seatalk ng tee in this Seatalk ng backbone, a normal Garmin NMEA 2000 tee in the NMEA 2000 backbone and connect these two backbones tee's with a Raymarine Adapter cable (A06046). Is that right? Did you power this setup (dual backbone) with just one power T in the NMEA 2000 backbone? Thanks again for your help. JC

  • You can't have dual backbones unless you use a bridge which passes data between the two but keeps the power segregated. I doubt you want to get that complicated, so either you want a standard N2K backbone with the Raymarine gear teed into it using STng-to-Devicenet adapter cables or an STng backbone with your Garmin gear teed in using Devicenet-to-STng adapter cables. I tend to get confused about the plug genders of those cables, but it was all worked out in this thread:

  • Yea the dual backbone didn't sound right. I see how to tee the ST70 AP controller into the N2K backbone but how did you tee the SPX30 corepack TO THE N2K. The SPX30 has that special 90 dregree plug (SPX Spur cable) that plugs into the SPX30 at one end and has a STng male connector at the other. The Devicenet-to-STng adapter cable has a STng male connector on it also.

  • I don't have dual backbones - too complicated for my taste. I have a Seatalk-NG backbone. From a Seatalk-NG tee on the Seatalk-NG backbone I have a Raymarine seatalk-ng to nmea2K stub adapter cable. This cable plugs directly into the back of the Garmin plotter. The raymarine adapter cables are available as male or female NMEA2K plug versions. I don't recall which gender you need for the Garmin plotter. I remember that I bought one of each to be sure - the cables are relatively cheap.

  • Helimech, I had that same issue with Raymarine's now obsolete AIS500. It didn't have an STng port I could plug an adapter cable into. So I just cut off the white STng plug and spliced on a devicenet cable. I could have used a field-attachable male connector if I had had one. Worked fine! Here's an entry showing the wire colors you'd splice, which are pretty obvious anyways:

    PS for lurkers: here's the dope on the two different STng adapter cables:

    Part Number A06045
    DeviceNet female adaptor cable
    Connects NMEA 2000 products to an STng backbone

    Part Number A06046
    DeviceNet male adaptor cable
    Connects SeaTalkNG products to a NMEA2000 backbone

  • Just to circle around on a couple things. I'm told you MUST HAVE a ST70 with the SPX in order to have comm on with a N2K network. You cannot just tie the SPX to the N2K. I have a Garmin backbone and tried the later. Another value add from Raymarine.

    Instead of buying a $500 ST70, I went with the N2K/N0183 converter. However,I have poor results with the speed to update information when running AP off of AWA. Hope that helps.

  • Hmmm, I guess it's possible that the SPX30 just doesn't use N2K if it doesn't see an ST70 pilot head on the STng network, instead using plain SeaTalk where the head must be. I don't see anything about that restriction in the manual, but it is a difference between your system and Roy's. Was it Raymarine who told you must have an ST70 head for any STng/N2K communications?

  • The information was from our local Raymarine dealer. I did follow up with Raymarine tech support who did confirm. Nothing in the manual was one of my peeves also. I'm considering the change if it'll speed up comm and allow the AP to control to AWA, but I'm trying other options first... and will take suggestions. Thanks for the info on cables, etc.

  • Thanks also from me on the cable color info. So I guess from what I think I'm hearing I just tee the ST70 into the N2K backbone using the Devicenet adapter cable then I slice the cable from the SPX30 into a N2K drop cable just matching wire colors. Is this right?

  • I think that's it, Helimech. Then you'd have the same setup as RoyHB, data wise, and the data really doesn't know what sort of cable it's travelling on.

    I think what we've learned from Petecc37's experience is that the SPX30 does not listen to the STng/N2K network unless it's being controlled from that network instead of regular SeaTalk. That's a better explanation of the problem Wayfarer had then my first stab in early comments.

    Everyone should also note that the ST70 pilot head is being replaced with a choice of p70 heads, which look like a nice upgrade.

  • This is getting too complicated for me. I assumed (maybe I was wrong) that you wanted to add a Garmin plotter to an existing SeatalkNG network - now it sounds like you want to add a Raymarine autopilot to an existing NMEA2K network. Whichever direction you're going, in my experience it works. It's easy to over-complicate it. SeatalkNG and NMEA2K are, as far as I and others can tell, electrically identical and plug into each other just by using the appropriate adapter cables or field installable connectors.

  • I just wanted to know how you guys hooked up your SPX30's to a N2K network. I don't see how to do it without splicing the SPX30 Spur cable to a standard N2K drop cable.

  • This thread is working on two different issues at once, which why it seems confusing.

    Helimech, yes you can turn your special SPX30 STng spur cable into an adapter cable by splicing it to a micro size devicenet cable with a male plug or, perhaps better yet, by using a male micro field-attachable connector. Maretron is the main source of these, and I notice they are now offering 90 degree models as well as the standard straight ones:

    Note, though, that no one here has actually adapted an SPX cable to devicenet. I did it with a Ray AIS500, but haven't tested an SPX; Roy is using STng cabling with Garmin 740 patched in; and Peter is trying other protocols because the SPX apparently won't listen on STng/N2K unless an ST70 or p70 control head is online.

  • I did put a Garmin field installable connector on a Seatalk-NG cable at one point - it worked fine.

  • Didn't mean to screw up thread but I saw the last entry was last March so figured it was dead. Thanks to all for your comments. I'll let you know how it works.

  • "Any ideas as to what's going on? The data appears to be broadcast out, but the SPX is not listening. Let me know what you think."

    MNEA 2000 is not broadcasted out it is requested. "The SPX" on NMEA 2000 dose "not listen"

  • Hi All,

    Raymarine use proprietary messages to control the autopilot by SeaTalk NG (NMEA 2000). So, SPX30 will work with Raymarine chart plotter or pilot head only. Or with Yacht Devices products ;)

    We added the special support of SPX30, EV-1 and other SeaTalk NG autopilots to our wi-fi, usb and NMEA 0183 gateways:

    For example, you can connect our NMEA 0183 gateway to 0183 tx of Garmin to control the autopilot. Other way is to connect autopilot to Garmin by NMEA 0183, it should work.