Wattsonic Hybrid Inverter Gen3 Modbus RTU Protocol

7 Comments

• Hey
  Thanks, great information, very helpful.
  I’m owning an M-Tec system (the same, just different badge) and I’m currently trying to decipher some of the values and there are two that confuse me, maybe you got some more experience and you can help.
  What is Invt_A_P (And B and C of course)? In total it’s always up to 100 W above the sum of PV power and battery power. PV power and battery power are matching the values in the official dashboard, so I do trust them, at least as far as you can trust companies and their dashboards. Might it be the inverter power including heat losses? The inverter has a big heat sink and it is still above 40 °C, so that might match. I’ wouldn’t be surprised at all if the company hides the system losses in its dashboard. What’s your experience, do you think that might be right?
  Second items isn’t that important, just confusing: Backup power is always something like 60 W, though the backup line isn’t even connected. I guess that’s a measurement error, probably tolerances on the current sensors, plus maybe something like a tolerance compensation to be sure to never get a measurement below the real value. Do you see something similar?
  Hm, while writing this, I begin to wonder if the things might be related, with the system pulling it’s own power demand from the backup line.

  Cheers,
  Holger

  Reply

  • Hi Holger,
    Invt_A_P (And B and C of course) translates to Inverter_L1_Power, Inverter_L2_Power and Inverter_L3_Power in Germany and is simply the english naming convention for the three phases in use. It represents the AC output power of the inverter per phase and is not directly related to either PV power nor battery power.
    You don’t find these values on the overview page of the app or webpage, but you can see it under Devices -> realtime information in the “inverter AC parameters” block

    Regards,
    Martin

    Reply

• Hi, thank you, this site helped a lot. I also wanted to connect via Modbus TCP, this worked for me at the end (i just used QModMaster):
  Slave-IP: IP of the Inverter (device “espressif” on the router)
  TCP-Port: 502
  Modbud Mode: TCP
  Unit ID: 255
  Read Holding Registers (0x03)
  Start Address: e.g. 33001 for the charging state (you must add 1 to the register number)

  This should word on Wattsonic inverters Gen3, M-Tec Gen3 and some other brands with the same inverter inside.

  Reply

• Hi,
  thanks for the Wattsonic template and documentation. I want to change the “Grid Injection Power Limit Setting” register value, it is read/write register. I have imported the Wattsonic template into Loxone Config, but the register is not listed in actuators only in sensors. I can read it but can not write into it.

  Am I missing something? Using wrong template version,…

  Jan

  Reply

  • OK, got it. The template does not contain all the read/write registers, but I can add them myself.

    Reply

• Good day,
  may i know what register is for the current % battery level? I can not find it.
  Thank you

  Reply

• I confirm that modbus TCP via lan dongle works and there is no need to use RS 485 at all.

  Reply