modbus communication with arduino uno


i am trying to communication with modbus to arduino uno. i am working on this instrument( and i am trying to get data on arduino. But i am not getting any kind of data and i am attach serial monitor screen and code so help me

_26y.ino (1.2 KB)

  mySerial.write("req, sizeof(req)");

I doubt seriously that the device understands that string. What possessed you to put the quotes there?

    Serial.println(byte(RS485Byte), DEC);

Why are you finding it necessary to cast a byte to a byte?

thanks for reply pauls

i am finding code of modbus and combine it. i am try so many code but not get data on arduino. if any change in code you told give me suggestion and help me. please

Did you remove the double quotes from that statement? If not, you are wasting my time.

thanks pauls.
but i am not getting any data.
i am not wasting any one time but i want to solution how to get data on arduino from modbus rs485. how to get data please help me please

any budy help me,
how to modbus data get on arduino uno?
i am trying so many time but don't get data on arduino.Any kind of suggestion and code you have so help me

how to defined modbus register address in arduino?
how to read and write data on register in arduino?