[SOLVED] SignalK and SeaTalk1 total log 0x25

[tjm]

Hello,

I have been pondering why my total log value shown in my ST1 log gauge and Signal K are not identical.
The gauge shows 11451NM and SignalK about half less.
The gauge is Raymarine ST60+, attached on the boat year 2006.

Plugged the STALK_read.py today and the total log datagram (25h) was stable and its value was:

25h 14h 4Ch BFh 00h 00h 00h 

According to Thomas Knaufs "SeaTalk-2002.pdf" the last 3 NULLs are the trip value, and NULLs are ok as the boat was stationary.
The document states that the total log is calculated as: "total= (XX+YY*256+Z* 4096)/ 10 [max=104857.5] nautical miles".

Putting the values in: XX =4Ch =76d, YY =BFh =191d, and Z =10h =16d we get
(76 +191*256 +16 *4096) /10 =11450,8 and that is exactly what the ST60+ gauge shows.

So I dug into SignalK and found this page: https://github.com/SignalK/nmea0183-sign...lk/0x25.js
In the file "0x25.js" there is the calculation for the total log value.

It seems first OK, except that the value Z is first bitwise anded by value F0h (14h becomes 10h) which is correct, but then it is shifted 4 bits to the right (10h becomes 01h).

So is the shift by 4 to the right correct because that corrupts the total log value?
But honestly I do not even know for sure that the "0x25.js" is used in SignalK...

with best regards to all,
tjm

[Sailoog]

Good catch

https://github.com/SignalK/nmea0183-signalk/issues/248

[tkurki]

Fixed (I hope!) in @signalk/nmea0183-signalk@3.14.1, run

npm install -g signalk-server

to pull in the latest version.

[jim321]

That was fast.

[tjm]

Yes it was, Big Thanks !

Had to use command "sudo npm install -g signalk-server" as without sudo there was complaints of privileges.

Back to test with the ST1-network on start of November, will report back.

wbr,
tjm

[tjm]

Did the testing today and the log value is now correct.

A few observations though concerning the Instrumentpanel.

The boat is stationary, no movements.
After Seatalk1 startup the IP shows correct values for the log (11451) and the trip (0.0).

After a few minutes the datagram 0x25 changes to "0x25 0x00".
About at this moment the IP starts to show a value "null" for the log and the trip.
The ST1 instruments still maintain the correct values for the log (11451) and the trip (0.0).

Is it possible to discard the datagram "0x25 0x00" and use the "last known sensible value" for the log and the trip?

Noted also that the trip-widget does not show the value unit in the lower right corner.
Also it does not have a unit selection at all (metres, nautical miles).
If I recall correctly it seemed to show the trip-value in metres.

Is there a way to correct these ?

But thanks a bunch for the log value correction !!

Cheers,
tjm