OpenCPN and SPX Autopilot

[SUNSHINESAILOR]

g'day all,
i have opencpn connected to a Raymarine SeatalkNG bus using an Actisense NGW-1 - this seems to work ok as the P70 AP controller displays BTW,DTW, COG, SOG and i can read HDG back from the SPX10 AP.
My problem is that when I select TRACK on the P70 it says that there is "No Navigation Data".
Can someone please give me some insight into what the AP is looking for?
cheers
ian

[ChuckSK]

ian

SPX autopilots are very picky when operating in NMEA2000 track mode. The SPX requires a NMEA2000 PGN 129284 that contains "Bearing origin to waypoint", "Origin waypoint number" and "Destination waypoint number". If these fields are missing you will see the "No Navigation Data" message. The Actisense NGW-1 does not fill in these fields when it converts the NMEA0183 RMB message to NMEA2000 PGN 129284.

So no joy in connecting OpenCPN to SPX with NMEA2000.

Chuck

[marathona]

I had the same problem with my SPX-5. The reason with mine was, that the SPX needs the magnetic deviation (I am not sure if this is the correct word in English) included in the NMEA RMC data set from OpenCPN. I solved it by installing and activating the "World Magnetic Model" plugin.

[SUNSHINESAILOR]

Thanks Chuck, i really appreciate your advice.
I'm not sure if my last reply got thru but I have changed to sending NMEA0183 into the SPX NMEA port.
The issue now is that the LH (Locked Heading?) on the AP controller flicks up to about 30 degrees either way from the BTW before settling down to a figure equal to BTW + VAR although all the units are in Magnetic.. also does weird things in True as well..
I'm interested in how the LH (heading) is being derived and who by? (SPX or Opencpn?) I'm sailing under spinnaker between lots of roscks so it's not so easy to do analytical testing
I have emailed Actisense to see whether they intend to fix the 129284 issue..
thanks and cheers,
Ian

[ChuckSK]

The problem is not with Actisense. The NMEA0183 RMB message does not contain the missing values.

OpenCPN will send RMC, RMB and APB messages to the autopilot. Check out the definition of these messages.

[SUNSHINESAILOR]

ok, thanks Chuck. So it sounds like the missing 129284 values need to be parsed from multiple 0183 messages? On their Gateway Conversions (issue 2, 199) they show APB + RMB both going into 129284...
I have the pilot running from Opencpn with nmea0183 connection direct to SPX but now have the issue with erratic set heading data when in TRACK mode..
at least it stops one getting bored just sitting on a tropical beach...

[glambx]

I myself have just brought a p70 up to opencpn via a Maretron USB100, and while I can see the autopilot's messages (and magnetic heading in opencpn), nothing I do seems to send anything back to the autopilot.

DTW, XTE, etc., are all blank, and of course track doesn't work.

Any NMEA2k / Maretron / p70 experts out there with suggestions?

[SUNSHINESAILOR]

hi, just checking that you have "activated" your route? (right click on route)
And that you are seeing the "this leg" box on your screen?
Next is to configure an output under tools.
Make sure that APB, RMB and RMC are checked.
I'm not sure what the USB100 does but are you connecting directly to the course computer or the P70?
With NMEA0183 you would have to go directly to the terminals of the course computer unless the USB100 is a converter. The P70 only accepts Sea Talk or STng.
I have tried all variations over the past year and discovered shortcomings in the AP, converters and I think a heading bug in OCPN (which I believe is fixed in the latest Beta)
Hope this helps..
cheers
ian

[glambx]

Originally Posted by SUNSHINESAILOR

hi, just checking that you have "activated" your route? (right click on route)
And that you are seeing the "this leg" box on your screen?
Next is to configure an output under tools.
Make sure that APB, RMB and RMC are checked.
I'm not sure what the USB100 does but are you connecting directly to the course computer or the P70?
With NMEA0183 you would have to go directly to the terminals of the course computer unless the USB100 is a converter. The P70 only accepts Sea Talk or STng.
I have tried all variations over the past year and discovered shortcomings in the AP, converters and I think a heading bug in OCPN (which I believe is fixed in the latest Beta)
Hope this helps..
cheers
ian

Hi Ian,

Thanks for the response!

I've tried activating an existing route and using the "Navigate to here" menu item; in both cases the route display becomes active showing cross track error, distance & bearing to waypoint, etc.

I've configured the NMEA port for output and tried playing with the filters (both include and exclude), and I can see traffic coming in from the USB100 (rudder position, magnetic heading, etc), and according to the NMEA debug window, stuff going out as well. It just seems the autopilot is ignoring them.

When you say "configuring an output under tools" do you mean the NMEA connections? Or is there some other panel I missed to actually enable output from opencpn?

The USB100 speaks native NMEA2000, converts to/from NMEA0183, exchanging the latter with a PC via USB. It's possible that some messages aren't being converted properly, but not sure how to check that.

I have it hanging off a 3-port STNG connector near the sensor core, trunked back to the p70.

[SUNSHINESAILOR]

it sounds like you have all the OCPN bits set right but have the same issues i had when using an Actisense converter - see Chuck's comments in this thread - so you might have to talk with Maritron about their conversions... also try the latest Beta of O and see if that works better...
When i get back to my boat later in the year i will be having another go because Actisense have just upgraded their firmware and believe they have fixed the issues.
What type is your AP Course Computer? Raymarine SPX?
According to Chuck, this unit is very fussy about what it receives in the NMEA2000 so it might make sense to capture the output of the USB100 and send it to the Raymarine tech forum and ask what's missing, and then see whether it's Maritron or OCPN that's not playing properly.
The Actisense guys also pointed out that NMEA2000 doesn't like Alpha characters in waypoint names so they could only handle numbers - this could also be causing you grief as well if your waypoint names include letters..
Sorry I can't be more helpful right now.
cheers
ian

[SUNSHINESAILOR]

I just came across this reply on the Raymarine tech forum... it could have something to do with why some of us have problems feeding non-RM NMEA2000 into the SPX/P70... he recommended that the client connect his SPX to his NMEA2000 chartplotter using NMEA0183..

Permalink Reply by Underway - Raymarine, US on November 26, 2012 at 12:53pm
I understand your frustration when working with multiple manufacturers of electronic equipment and having them communicate and work together. The SPX autopilot course computers were never NMEA2000 devices when they were released in 2009, hence the recommendation for connecting NMEA 0183. With the e97 question, the new e/c/a Series displays and p70R are NMEA2000 devices and will communicate and work on N2K backbones.

- hopefully the SPX firmware has been updated since then..

cheers

[glambx]

Originally Posted by SUNSHINESAILOR

it sounds like you have all the OCPN bits set right but have the same issues i had when using an Actisense converter - see Chuck's comments in this thread - so you might have to talk with Maritron about their conversions... also try the latest Beta of O and see if that works better...
When i get back to my boat later in the year i will be having another go because Actisense have just upgraded their firmware and believe they have fixed the issues.
What type is your AP Course Computer? Raymarine SPX?
According to Chuck, this unit is very fussy about what it receives in the NMEA2000 so it might make sense to capture the output of the USB100 and send it to the Raymarine tech forum and ask what's missing, and then see whether it's Maritron or OCPN that's not playing properly.
The Actisense guys also pointed out that NMEA2000 doesn't like Alpha characters in waypoint names so they could only handle numbers - this could also be causing you grief as well if your waypoint names include letters..
Sorry I can't be more helpful right now.
cheers
ian

Sorry for taking so long to reply; had some connectivity issues out at sea.

I'm going back and forth with Maretron support; hopefully they'll have some suggestions. The strange thing is, even if the P70 uses proprietary/picky autopilot PGNs, it should definitely accept the translated $GP sentences. I should be seeing lat/long data, if nothing else, so it feels like the USB100 just isn't forwarding anything at all (or opencpn isn't).

I'm running a Ray EV-100 "evolution" autopilot, so I'm not sure where exactly the course computer is. It's got a p70 display head, an EV-1 sensor core (guessing this is it), and an ACU-1 autopilot control unit.

I'll let you know if I make any progress!

[werner.thon]

Hello everybody,

I am trying to use my SPX5 with OCPN on a WINDOWS 7 tablet. The USB
output is connected via a ShipModul Miniplex Lite to the NMEA input of the
AP. With the OCPN output set to $ECRMB and a route activated the output
is something like

$ECRMB,A,0.001,R,001,002,5431.307,N,00941.537,E,1. 488,31.551,0.104,V*32

The AP displays the contents (ID of next waypoint, XTE, BRG, RNG) on its
data pages, but it refuses to switch to TRACK mode. According to the
Raymarine support (in Germany) this is due to the lack of one more data
field within the RMB sentence. It should look like

$ECRMB,A,0.001,R,001,002,5431.307,N,00941.537,E,1. 488,31.551,0.104,V,A*32

with the A just left of the checksum star beeing the 'mode indicator' as
specified from NMEA 2.3 on. Raymarine support says, this data field is
mandatory for the SPX5 to switch to TRACK mode.

Anybody knows a solution?

greetings Werner

[ChuckSK]

Hi Werner

You also need to send the $ECRMC sentence to the AP. The $ECRMB sentence is fine.

Chuck

[werner.thon]

Hi Chuck,

thanks for the advice!

I have set up OCPN to output both RMB and RMC sentences, but this does
not help.

I have also -with a NMEA simulator program- sent some fake RMB and RMC sentences, with and without additional 'A' field, without success...

The NMEA simulator (Nema Talker, Sailsoft AIS and NMEA simulator software) is a very handy and helpful tool btw!

Werner