Signal K Filter

[Lazzz]

I am have trouble getting my head around the filtering of data going to SK.

To filter say, navigation.position:latitude would I Filter on Source = sentence
Value would be say GGA or GLL or RMC
Max timeout[s] = ?

Do I put all 3 Sources (GGA;GLL;RMC) in with different timeout values??

Could someone give me an example how to use say, RMC as my preferred source & then next preference say GLL then GGA as final preference for this data going to SK.

These sources don't cause any problems but when I have my Raymarine MFD running I get way too much data coming in & it slows SK right down or sometimes freezes so I need to filter some sources.

   

[Lazzz]

Anyone??

[SCarns]

I'm not sure prioritizing individual sentences is purpose of SK Filtering.

My limited understanding (for what that's worth) is to give priority to devices sending the data, rather than giving a priority over sentences. For example, I have two devices that send "position" information, a chart plotter and an AIS. Obviously that causes an issue and a "flicker" on the chart as each devices sends slightly different location information, and SK uses "last-in" info. So filtering would allow SK to prioritize one device (chart plotter) over the other to focus on that info, while using the other (my AIS) as a fall-back in case the first one drops out after a predetermined time.

Is your Raymarine CP connected to SK over a serial bus? If so, I'd assume it's set at 4800 baud, which wouldn't slow SK down. My SK processes over 430 paths a second connected to various serial and can buses with my Raymarine CP pumping in a lot of data over SeatalkNG. The RPi SK runs on barely breaks a sweat. I'd guess in your set up something's not right...

Perhaps you have a data loop and you are "recirculating" NMEA data out and back into SK. Data loops are deadly and can certainly bring SK to its knees and make it crawl.