Twocan - a new Plugin

[stevead]

The current version of OpenCPN 5.8.x, does support NMEA 2000.

Refer to the following post

For Windows & Mac users, the Actisense NGT-1 and Yacht Devices YDNU-02 adapters are supported.

For Linux devices, both of the above and any interface that supports SocketCAN are supported.

As has been stated before, only direct wired connections to the NMEA 2000 network are supported.

Neither OpenCPN nor TwoCan plugin support non-standard proprietary transmission of NMEA 2000 over TCP/IP (be it Ethernet or WiFi) or "wrapping" of NMEA 2000 messages within NMEA 183 sentences.

[mpuz]

I wouldn't agree about direct wired connection, i have just succeeded to feed nmea2000 dump from my can bus home setup to the OpenCPN running on ubuntu laptop using Bluetooth serial custom made device which only uses incredible library from Timo Lappalainen with just one major line

NMEA2000.SetForwardStream(&SerialBT);

https://www.youtube.com/watch?v=ZPexQ8Dr09I

[mpuz]

my opencpn installed from official repository does not have twocan plugin, do i miss something?

[stevead]

my opencpn installed from official repository does not have twocan plugin, do i miss something?

No, you are not missing anything.

Time, sailing commitments & holiday festivities permitting, I hope to publish a new release very soon.

For those that can't wait for an official release to the plugin manager catalogue, the v2.2 tarballs may be downloaded from cloudsmith

[GreenHeaven]

I have read most of this thread
I am still not clear if i can use this CAN adaptor
https://www.amazon.com/gp/product/B0CDGGBZDT

and if it will provide ALL the N2K messages on the network to my windoz PC?
I am particularly interested in Raymarine EV-1 messages
I want to be able to use the autopilot plug in in OpenCPN

I also want to parse the messages sent between the RM devices possibly with wireshark etc

[stevead]

An interesting question....

Just to clarify, your OS is Windows and your autopilot is a Raymarine EV-1

At the moment, the only way to control an EV-1 natively is via the AutoTrack Raymarine plugin

That plugin uses the native NMEA 20000 support in OpenCPN.

The list of natively supported NMEA 2000 adapters can be found here

A you can see, only the "intelligent" adapters are supported on Windows, so that precludes the CAN adapter that you mentioned.

On the other hand, as you have possibly noticed, the TwoCan plugin does support a different range of adapters, including the Canable Cantact, which I presume is what the adapter you are interested in, is based upon.

Whether that adapter is recognized by the automagic™ adapter detection in TwoCan is unknown as they may use a different Vendor ID/Product ID (VID/PID) to what is used in the original Canable device.

Also at this point in time, the TwoCan plugin does not have "official, public" support for autopilots. However, if you are interested in following up please feel free to PM, as there is unreleased/untested support for both Raymarine Evolution & Navico (NAC-3/NAC-2) autopilots.

[stenhh]

Hi there,
using the Toucan marine adapter together with OpenCpn to filter NMEA 2000 messages to NMEA 0183, the class B messages seems to be incomplete. The vessel data seems to be missing even after using OpenCpn for some time.
The vendor of the Toucan marine adapter says the adapter is only a transparent bridge between the CAN bus and the USB interface. It does not filter any CAN frames.

May I kindly ask for your advice on how to proceed to fix the issue.


Please see attached image:




Regards
Sten-Helge

[stevead]

Just to clarify.

You are using the Rusoku Toucan adapter with the TwoCan plugin?

If so, what Operating System & version, what version of OpenCPN and what version of the TwoCan plugin?

I am not aware of any reported issues parsing AIS messages, including PGN's 129039 (AIS Class B Position Report), 129040 (AIS Class B Extended Position Report), 129809 (AIS Class B Static Data: Part A) or 129810 (AIS Class B Static Data Part B).

If you can generate both a NMEA 2000 log file (from the TwoCan Settings-> Device Tab) and a NMEA 0183 log file (either from TwoCan Settings -> Debug Tab or OpenCPN -> Settings->Connections->NMEA Debug window) together with a copy of the OpenCPN settings and either post to the forum or send a personal message (PM), I'll have a look.

Thanks.

[stenhh]

Thanks for your support.
Here are some more details:

TwoCan plugin v 2.1
OpenCpn v 5.8.4
Ubuntu 22.04.4

Please find attached for your consideration:

opencpn_conf.pdf

twocan-2024-07-08_185807_binary.pdf

twocanplugin_nmea.pdf

Thanks
Stan-Helge

[stenhh]

... and just to clarify - I am using the Rusoku Toucan adapter with the TwoCan plugin.

[stevead]

Hi Stan,

Thanks for the logs.

I think I have an idea about the problem, however unfortunately the two logs don't exactly overlap. Also Class-B vessels only send static data every 6', so I may ask for a longer dump. (FYI, you don't have to save the logs as pdf files, just rename the text files with the .pdf extension to fool the forum upload system.)

Could you answer a couple of questions?

Firstly what is the MMSI number of your vessel. (Feel free to send as a private message if you're concerned about privacy).

Secondly what brand/model of AIS do you have ?

The nitty gritty. In the plugin, the same logic is used to determine if a Class A or Class B transmission is from another vessel (in NMEA 0183 parlance an AIVDM message) or from one's ownship (AIVDO). Clearly the logic for the Class A vessels is working correctly as their static data when available is displayed.

However for Class B vessels, and unfortunately there was only one sample in the log, the NMEA 2000 field for that information is being set by your AIS transceiver to 0x1F, (it's a 5 bit field so the value being sent is binary all 1's eg 11111). In the NMEA 2000 world, when a value, irrespective of its size is set to "all 1's" it means data unavailable.

I have never seen this before in any NMEA 2000 AIS messages I have received or tested.

The "bug" in the plugin, if you can call it that, is that the NMEA 2000 to NMEA 0183 conversion is being sent as an AIVDO "Own ship" message which is why the Class B Static data it isn't being displayed by OpenCPN. From my perspective a relatively easy fix.

I also think that there may be a bug in your AIS transceiver. Perhaps there is a firmware update available? Otherwise, if we can gather more data, you can advise the manufacturer of your AIS transceiver of the fault in their software.

Faults in AIS transceivers are not unheard of, a few years ago, another user in Seattle discovered a bug in an Icom AIS transceiver in that it didn't encode AIS Aid To Navigation names correctly. Icom, to their credit, did release a fix.

Thanks.

[stenhh]

Thanks for your support.

Here is some more details and logfiles taken approximately at the same time.

MMSI: 257509630
AIS transceiver: Garmin AIS 800 with latest software update v2.90


twocan-2024-07-09_143741.pdf

nmealog.pdf


Regards
Sten-Helge

[stevead]

Hi Sten,

These logs are perfect, greatly appreciated. Unfortunately they confirm what I originally suspected.

I can come up with a fix, however not sure when I will be able release it.

I have also asked some others whether a bug report should be submitted to Garmin as I've never seen AIS transceivers set the data fields like this before.

Thanks very much.