Список регистров Modbus, которые использует родное приложение. Часть описана в документации, часть нет
MB_READ_DISPLAY1 = 41;
MB_READ_DISPLAY2 = 42;
MB_READ_DISPLAY3 = 43;
MB_READ_INFO = 36;
MB_READ_M = 39;
MB_READ_M0 = 45;
MB_READ_M1 = 47;
MB_READ_M2 = 49;
MB_READ_M3 = 51;
MB_READ_M4 = 53;
MB_READ_STATE = 35;
MB_READ_SYSTEM = 37;
MB_WRITE_ADDRESS = 33;
MB_WRITE_CLEAR = 114;
MB_WRITE_DISPLAY = 44;
MB_WRITE_M = 40;
MB_WRITE_M0 = 46;
MB_WRITE_M1 = 48;
MB_WRITE_M2 = 50;
MB_WRITE_M3 = 52;
MB_WRITE_M4 = 54;
MB_WRITE_MODE = 32;
MB_WRITE_POWER = 34;
MB_WRITE_PROTECT = 80;
MB_WRITE_RESET = 97;
MB_WRITE_RUN = 113;
MB_WRITE_SYSTEM = 38;
MB_WRITE_ZERO = 96;