question

Hi Urban, those details are under NDA by the NMEA organisation; so can only be purchased from them; sorry.

Perhaps good to know that we are working to add transmission of NMEA2000 PGNs, including solar, to our Venus-device range.

Indeed, NMEA 2000 specifications are covered by NDA, but there are several projects where some of that stuff is reverse engineered. Please take a look at:

https://github.com/canboat/canboat/blob/master/analyzer/pgns.json

On the other hand, on my installation with Victron SmartSolar MPPT 150/70 VE.Can is sending over a CANBUS several frames, including PGN 127750 you were originally asking about, but the data portion of the frame includes SID changing in sync with PGN 127508, but remaining 56 bits (7 octets) makes not much sense to me:

(1714762196.504391) can0 19F30624#0DFFFCFDFFFFFFFF
(1714762198.004403) can0 19F30624#2BFFFCFDFFFFFFFF
(1714762199.504071) can0 19F30624#49FFFCFDFFFFFFFF
(1714762201.003996) can0 19F30624#67FFFCFDFFFFFFFF
(1714762202.504662) can0 19F30624#85FFFCFDFFFFFFFF
(1714762204.004305) can0 19F30624#A3FFFCFDFFFFFFFF
(1714762205.504137) can0 19F30624#C1FFFCFDFFFFFFFF
(1714762207.004291) can0 19F30624#DFFFFCFDFFFFFFFF

The resulting dissection by canboat "analyzer" looks like:

2024-05-03-18:49:56.504 6  36 255 127750 Converter Status:  SID = 0D; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:49:58.004 6  36 255 127750 Converter Status:  SID = 2B; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:49:59.504 6  36 255 127750 Converter Status:  SID = 49; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:50:01.004 6  36 255 127750 Converter Status:  SID = 67; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:50:02.505 6  36 255 127750 Converter Status:  SID = 85; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:50:04.004 6  36 255 127750 Converter Status:  SID = A3; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:50:05.504 6  36 255 127750 Converter Status:  SID = C1; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown
2024-05-03-18:50:07.004 6  36 255 127750 Converter Status:  SID = DF; Connection Number = Unknown; Operating State = 252; Temperature State = Warning; Overload State = Unknown; Low DC Voltage State = Unknown; Ripple State = Unknown

What is Operating State "252"?

Why Temperature State is "Warning"?

Which Temperature it refers to? MPPT or Battery?

What is the threshold between "Good" and "Warning" and "Bad"?

(BTW - Battery Temperature was 30C at the time, per CANBUS message 0x356 reported by BMS)

How to measure MPPT temperature? Is it even possible?

Too many question and no answers... If someone nows more (mvader?), please share with us.

Thanks,

Przemyslaw Karwasiecki

S/V Festina Lente