SMA SunnyBoy returns -1

Michiel Kenis 3 years ago in Devices / Modbus updated by Jürgen Jürgenson 3 years ago 3

I've just connected my SMA Inverter (SB3.0-1AV-41) using the ModBus protocol. Connection was made successfully, but all I retrieve from fetching values is -1 or synonyms (65535 for uint16, 4294967295 for uint32,...). 

I have some ModBus information on this specific inverter ( modbuslist_en.html), and I've tried to crosscheck this with the (slightly outdated) SMA-Modbus example on the Library, but no dice... I cannot read out values from my Inverter and start building my Solar dashboard... 

I'm using the bèta of bOS 4.8.0 and these are my settings for getting the value of Phase A, address 199 in the SMA datasheet, so I use 198 in bOS;

Image 2960

Image 2961

Advise or tips?

In the manual it says that "GridMs.A.phsA register 30977 Signed 32bit"... for Phase A. Is the register correct? Also if there is no sun it may not display any correct values. At least Fronius acts this way there should be operating state codes - try to get this to work first.

I've tried many Addresses... Here is my screenshot of the 977 (or 976) value on signed 32bit. Still -1 as value. 

And yes, there is sun :-) 

Try QModMaster or any other modbus scanner then to find out what registers are the correct ones. Also try turning off multi read and use the full 30977/30976 register.