Does other reading works well? Or it is just this register you can't read? Send us raw answer of Modbus reading of this register and we can figure it out...
This link shows that accumulated energy is stored in 64 bit registers, if you are reading 3204 and onward. Sorry about the complex link, I couldn't get to it without going through Google: https://www.google.com/url?sa=t&rct..._v2.1.0.xlsx&usg=AOvVaw1KQL427948lofQBlASDntU
Different meters store the same data in different formats, so you can't directly compare one with another.
Does other reading works well? Or it is just this register you can't read? Send us raw answer of Modbus reading of this register and we can figure it out...
Other readings like Voltag, Current, KW, PF reads perfectly well. Only thing i am unable to get is KWH, KVARH, KVA, KVAR.
Modbus raw data it self shows -1 value.
So time for some simple diagnostics. Temporarily swap the Modbus Address of a fully working meter with the part working meter, obviously making sure that it won't cause problems anywhere else in the system. If the problem stays at the original Modbus address then the problem is in your code. If the problem moves to the new Modbus address then the problem is in the original meter. Swap them back to original again. Probably stretching the apple thing a bit far, but there are Bramleys and Granny Smith, etc. Check the firmware versions of the meter, maybe this one isn't quite the same type of apple as the others or maybe it has a worm and is just faulty.
Other readings like Voltag, Current, KW, PF reads perfectly well. Only thing i am unable to get is KWH, KVARH, KVA, KVAR.
Modbus raw data it self shows -1 value.
I'm afraid that it is not raw data, or at least I was not clear enough. Send us Modbus response code you are obtaining. I'm afraid that you are receiving Modbus exception code/response.