Discontinuous position - speed without damping
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Hello everyone, the title to discuss two topics and ask your opinion or that of Ilker if he reads us; I recently started using SL which until yesterday ran on SK of Openplotter 3 on RB pi4, and I noticed that as long as I have an LTE connection the recording of the route is done correctly (unless RB decides to block) but if I lose the LTE connection the track stops resuming when I find the connection again and making a line without intermediate points. This makes me think that the SL Plugin on SK does not record the intermediate data in a buffer, is that so? Second thing observed in the tracks the wind speed sometimes has high values and not seen during navigation, this makes me think that SL takes the data from the N2K bus without any damping and records a data at a time that is not representative (in fact on my chartplotter there are settings for the damping of values read by the wind meter). Does anyone know this phenomenon? Thanks
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Saillogger does indeed buffer data locally when there's no internet connectivity, and this feature is widely used by many of our users. Could you share a bit more about what you’re observing?
Regarding the second point, we use some dampening to filter out outliers. However, its effectiveness can vary depending on the number of outliers and the precision of the instruments. So, while it helps, it may not be entirely foolproof.
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You can simply share the link to the log. For this problem though, troubleshooting may be necessary when you're underway and lack Internet connectivity.
The Saillogger plugin displays a status on the Signal K home page, showing information such as, "1 entry in the queue; last connection to the server was 8 minutes ago."
Entries in the queue represent data cached locally until an Internet connection is available. When the plugin is working and connected to the Internet, the number of entries in the queue remains low—typically below 2 or 3—as data is transferred to the cloud every couple of minutes, which is dynamically adjusted. If there’s no Internet connection, the count will gradually increase. This isn’t an issue; those entries will upload to the cloud as soon as the plugin detects connectivity.
However, if there’s no Internet connection and the entry count isn’t increasing, there may be an issue—possibly with GPS availability or readings from NMEA 2000 instruments. Enabling plugin debugging for Saillogger can provide insight into the issue.
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Thanks for the reply, I sent the link to the path, (https://saillogger.com/log/021878) I hope this is useful to show you what happened. Just thinking that the problem could be related to pgns that are not available on SK (navigation.position) due to hardware causes (heat for canbus) or RB that crashes, I switched to SK on Cerbo GX that I already have on board. I don't know if this system is more stable than the one installed on RB through Openplotter 3 which contains routines that I don't use and potentially causes crashes. Since I installed SK on Cerbo GX I haven't gone out yet, but I will first enable debugging which could help us in similar cases, the only thing is the debug logo coming directly to you?
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Diagnosing the root cause is challenging by reviewing the log alone. This log confirms that no position reports were received, but understanding why requires local troubleshooting on Signal K. It’s almost certain that Saillogger did not receive position reports during this period.
As you point out, possible causes include hardware issues or overheating on the Raspberry Pi, especially if it lacks heat sinks. The Cerbo GX and Ekrano GX have undergone more extensive testing for this purpose and are expected to be more reliable.
When plugin debugging is enabled, additional details will appear in the Signal K server logs. However, these logs aren’t accessible from the cloud instance, so you’ll need to review them directly on Signal K. If you can share the logs here, we’d be happy to provide further insights. Be sure to collect them while the issue is occurring, and check the Signal K status page for any indicators, such as a static number of entries in the queue.
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regarding the Navigation.Position pgn on the N2K bus of my boat although I saw two of them (129025 and 129039) SL told me that it did not have a GPS position, I solved it by activating in the Victron plugin on SK "Use de position from Venus Os", now I have a third pgn that also provides altitude, with this SL confirms the GPS position. So it is not easy to understand what is happening here too, why did SL not see the Navigation.Position pgn that I said above?
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What were the timestamps for
navigation.position? Timestamps are critical here. Signal K may display positions even if they aren’t being refreshed, but Saillogger will only use positions if they are actively refreshed. When you encounter an issue like this, please verify those timestamps.Generally, there’s no technical reason why a GPS position in Signal K wouldn’t appear in Saillogger. Saillogger retrieves data directly from Signal K, so as long as the position is present and refreshing (refreshing is essential), it should definitely capture it.
